【プロンプト付き】GeminiでもChatGPTでも使える！万能４コマ漫画の作り方

どっちでも使える！AIも、みんな違ってみんないい〜。

ミヤマ

5月 14, 2026

こんにちは！

明日の予定もまあまあ忘れがちな絶賛・双子育児中のミヤマです😂

先日「誰でも美人になる漫画プロンプト」がプチバズしまして、たくさんの「やってみた〜！」リプ、本当にありがとうございました🙏✨

👇元の投稿はこちら

漫画のプロンプトは↑の投稿ポストに全文記載しています。

で、今回はその第2弾。

Gemini でも ChatGPT でも、同じ呪文で4コマ漫画が作れる「万能版」 を（少し前に）作ったので置いていきます。

🎨まずは結果から見せちゃいます

題材は 「忘れもの兄弟」。

うちの双子もまあまあ忘れ物の常連でして…プリント、体操着、筆箱、ランドセル…毎週なにかしら届けてる気がする😂

それを、同じプロンプト で Gemini と ChatGPT に投げた結果がこちら👇

Gemini（Nano Banana）

ChatGPT

呪文は1ミリも変えてないのに、ぜんぜん違う仕上がりですよね。

ざっくり言うと、

🍌 Gemini はキリッと整った「万人ウケ系」

── 資料・スライド・パンフレットに混ぜても浮かない

🎨 ChatGPT はふんわり「エッセイ・共感系」

── SNS・ブログ・育児漫画みたいな温度感のある投稿に強い

ターゲットと載せ場所で使い分けるのが正解だと思います😊

🪄万能プロンプト、置いていきます

お待たせしました、本題の呪文がこちら。

コピペでどうぞ👇

Create a single vertical 4-panel manga page (4-koma format)
in a French children's book editorial illustration style.

[PAGE LAYOUT]
- Tall vertical page, smartphone ratio (9:16 or taller)
- Top margin: generous white space above the title
- Title area: centered at top —「忘れもの兄弟」in a wobbly,
  slightly uneven hand-lettered Japanese font as if written
  with a rough ink pen. Below it: "never the lunch"
  in tiny, messy cursive handwriting — like a quick pen note
- 4 panels stacked vertically in a single column
  — DO NOT place panels side by side
- Reading order: top to bottom (panels 1 → 2 → 3 → 4)
- Panel borders: wobbly, imperfect rectangles drawn with
  rough freehand ink lines — intentional breaks and gaps,
  lines that taper and disappear mid-stroke. NOT clean, NOT straight
- White gutters between panels
- Bottom margin: generous white space
  — NO page number, NO text at bottom
- Page background: clean white

[ART STYLE]
- French children's book editorial illustration style
  — reminiscent of a vintage French children's fashion editorial
  or Petit Bateau lookbook illustration
- Characters: small round heads with chubby cheeks,
  soft childlike proportions, 4 to 5 head ratio,
  short limbs, playful natural posture,
  minimal delicate facial features
- Line art: rough freehand ink lines with intentional breaks
  and gaps, wobbly imperfect strokes, lines that taper and
  disappear mid-stroke, visible hand tremor,
  scratchy gestural quality.
  Loose ink hatching on clothing shadow areas.
  Fabric patterns clearly drawn such as fine breton stripes
  or subtle checks on clothing
- Coloring: soft translucent watercolor wash layered over
  ink lines. Pale dusty tones. Color bleeds slightly beyond
  ink outlines in a natural watercolor way.
  Light is luminous and airy, not saturated.
  Wet-on-wet blooms and soft gradients in fabric areas
- Color palette: MAXIMUM 4 colors + ink lines + white
  #1 dusty rose (the panda's accents, bento furoshiki,
     forgotten items' highlight, warm shadows)
  #2 warm ivory (skin tone, morning light, genkan
     floor warmth, cheerful areas)
  #3 muted sage (school clothes, fresh morning
     feeling, cool shadows)
  #4 powder blue (randoseru backpacks, panda's
     dark patches, desk surfaces, gentle depth tones)
  Plus dark ink lines and white paper showing through
- Backgrounds: loosely suggested with a few quick ink strokes.
  A wobbly ink line for a door frame. Scratchy hatching
  for a shoe rack. A single loose line for a desk edge.
  NOT detailed environments — just enough marks to set the scene
- Overall feel: chic and understated, warm and approachable.
  The kind of illustration found in a vintage French children's
  magazine — delicate but full of personality

[CHARACTERS — CONSISTENT ALL PANELS]

TWIN BOYS (age 6-7, first graders):
- Drawn in the French children's book editorial style.
  Small round heads, chubby cheeks, soft childlike proportions
- Two boys, same height, clearly twins but distinguishable.
  Twin A: slightly messier hair shape, body tilted or
    leaning — always in motion, always slightly off-balance.
    The one whose randoseru is always open
  Twin B: slightly neater hair shape, stands a bit more
    upright but equally forgetful. Quieter body language
- Hair: drawn as soft rounded ink shapes with loose hatching.
  A simple rounded mass with a few gestural ink strokes.
  Watercolor wash in layered dusty rose and powder blue
  creating a soft dark-brown appearance.
  Noticeably darker than their skin — reads clearly as dark hair
- Face: minimal delicate features. Small dot eyes or simple
  oval eyes with tiny ink highlights. Rosy circle cheeks in
  dusty rose watercolor wash. Mouth: tiny ink line that changes
  per panel — neutral, small O (surprise), cheeky grin.
  Nose: a single tiny dot or nothing at all
- Body: child proportions, 4 to 5 head ratio, short limbs.
  Head oversized compared to body. Playful natural posture.
  Kids are always slightly off-kilter — leaning, reaching, fidgeting
- Clothing: simple school outfit drawn with loose ink lines.
  White short-sleeve shirts (white paper + ink outline),
  with subtle breton stripe or fine check suggestion.
  Shorts in muted sage watercolor wash.
  School-issued yellow safety cap: a loose wobbly ink circle
  on the head or forgotten on the ground
- Randoseru (school backpack): drawn as a boxy rectangle
  on their backs with two strap lines.
  Powder blue watercolor wash fill. Loose ink buckle marks.
  Sometimes drawn OPEN with a textbook sliding out

TSUKKOMI PANDA:
- A small panda drawn in the SAME French children's book
  editorial style. Simple, round, chic.
  About 1/3 the twins' height
- Shape: a rounded circle body, round head, two small
  round ear bumps on top. Drawn with the same ink lines
  as everything else
- The panda's dark patches (ears, eye patches, arms, legs):
  filled with powder blue watercolor wash
  — NOT solid black. Keeping it soft and consistent
  with the editorial palette
- The panda's white areas: bare paper or faintest warm ivory wash
- Face: two powder blue eye patches (loose ink ovals),
  tiny dot eyes inside them, a small inverted-Y for
  nose and mouth. Expression changes through the tiniest
  mouth line adjustments — flat line = deadpan,
  slight downturn = unimpressed, no change = maximum
  panda energy
- The panda's commentary appears in wobbly ink speech bubbles
  or floating text in the same hand-lettered ink style.
  The panda's text is slightly smaller than the twins' —
  deadpan, observational, never excited

[STORY — 4 panels, top to bottom]

Panel 1 (top) — MORNING CHAOS / ESTABLISHING:
Bright morning at the genkan (entryway).
Twin A is rushing out the door, one shoe half-on (shoe
drawn as a simple ink shape, laces as loose scribbles),
shirt untucked (a few extra ink lines poking out).
His randoseru is on his back but OPEN — a wobbly
rectangle shape of a textbook is visibly sliding out.
Twin B is behind him, patting his pockets with a
confused dot-eyed expression.
On the genkan floor: a crumpled PRINT (school handout)
lies forgotten — drawn as a wobbly ink rectangle with a
few scribble lines for text. Dusty rose watercolor wash
highlight on the print to draw the viewer's eye.
Shoes scattered: simple ink shapes, one on its side.
The panda sits on the genkan step — small, round, calm.
Completely still while the twins are in motion.
Background: door frame as loose ink lines.
A shoe rack suggested with horizontal ink hatching
and a few shoe shapes. Morning light suggested by
warm ivory watercolor wash near the doorway.
Floating sound effect in ink:「バタバタバタ」
near the twins' feet — wobbly, energetic lettering.
Small floating text from the panda, no bubble:
「…あ、プリント」
The panda notices. The twins don't.

Panel 2 — AT SCHOOL / THE DISCOVERY:
Classroom setting — a desk edge (loose ink line),
a window (ink rectangle with muted sage wash for daylight
outside), chalkboard suggested with a few ink lines.
Mostly white space.
The twins stand side by side with sheepish expressions.
Twin A: holds up empty hands — his gym clothes bag is MISSING.
Expression: mouth drawn as a small O, dot eyes slightly wider.
Twin B: reaches into his open randoseru and pulls out nothing.
Pencil case is gone. Expression: tiny downward ink curve for mouth.
The panda stands between them at desk height
(standing on a desk or chair — a flat ink rectangle).
Small panda arms slightly raised — the tiniest gesture of
exasperation.
Color: warm ivory on skin. Muted sage on their shorts.
Powder blue on the open randoseru showing its empty
interior — the emptiness is the joke.
Speech bubble from Twin A (wobbly ink oval):
「体操着がない！」
Speech bubble from Twin B (smaller wobbly oval):
「筆箱も…」
Speech bubble from the panda (smallest oval, flat tone):
「きょうも何か忘れてる」

Panel 3 — THE LIST GROWS / MONTAGE:
The twins are drawn SMALL at the far left, increasingly
embarrassed — heads slightly bowed, loose ink shame-lines
(short diagonal marks) near their heads.
Scattered across the panel from left to right, each
item drawn as a simple ink vignette with watercolor wash:
  - A crumpled print (dusty rose wash)
  - A gym clothes bag, empty and deflated (muted sage wash)
  - A pencil case (powder blue wash)
  - A WHOLE RANDOSERU — they once forgot the entire
    backpack (powder blue, drawn slightly larger
    than the other items, with a big wobbly ! next to it)
  - An umbrella (ink outline only)
Each item has white space between them — like evidence
laid out on a table.
The panda stands at the far right of the panel, facing
the viewer. One small round paw raised as if presenting
evidence. Flat dot-eyed expression. Maximum deadpan.
Floating text from the panda in ink, spread across
the upper area of the panel:
「プリント、体操着、筆箱、ランドセル…」
Each word slightly different in size — hand-lettered unevenness.
Below the list, smaller panda text at far right:
「毎週なにか届けてる」

Panel 4 (bottom) — THE PUNCHLINE:
The scene shifts completely. Peace.
The twins sit side by side, each holding their BENTO
(lunch box) with both hands. The bento boxes are held
close to their chests — protectively, lovingly.
Their expressions: dot eyes bright and content.
Mouths drawn as small upward ink curves — satisfied,
slightly smug little grins. Rosy cheeks extra pink
(dusty rose wash applied more generously).
The bento boxes are the MOST COLORED objects on the
entire page — dusty rose watercolor wash fills the
furoshiki wrapping cloth generously, with visible
watercolor bloom and wet-on-wet texture. Warm ivory
on the box edges. The bentos GLOW with color.
They are drawn slightly larger than realistic proportion
— because to these boys, the bento IS the biggest thing.
The twins' posture: symmetrical, settled, secure.
Sitting properly on a bench (single loose ink line).
Nothing is falling. Nothing is open. Nothing is missing.
Just two boys and their lunches.
The panda sits between them, facing the viewer.
Chin resting on one paw in total deadpan resignation.
Color: warm ivory on skin, more generous than earlier
panels. Muted sage on clothes. Dusty rose on BOTH
bento furoshiki — the strongest, most saturated
watercolor wash on the entire page. This is the
visual punchline: all that scattered, muted color
from Panels 1-3 has concentrated into two glowing
lunch boxes in Panel 4.
Background: minimal. A bench line. White space. Calm.
Speech bubble from Twin A (wobbly ink oval, proud):
「お弁当は持った！」
Speech bubble from Twin B (wobbly ink oval, content):
「ぜったい忘れない」
Floating text from the panda, near the bottom:
「…それだけは絶対に忘れない」

[TYPOGRAPHY]
- Title: hand-lettered with rough ink pen,
  slightly wobbly — as if written quickly but with care
- English subtitle: tiny messy cursive below title
- Dialogue: same hand-lettered ink style inside wobbly bubbles.
  Twins' text: slightly larger, slightly messier.
  Panda's text: slightly smaller, slightly more even
  — reflecting its flat, measured delivery
- Floating text: smaller version of the ink lettering,
  no bubble — floating freely in the panel
- Item list in Panel 3: hand-lettered, spread horizontally
- ALL text is in dark ink, matching the linework.
  No digital fonts anywhere

[FORBIDDEN]
- Clean, uniform digital lines
- Solid black fills anywhere — ink lines only, no filled blacks
- Realistic proportions or anatomy
- Detailed realistic backgrounds
- Flat digital coloring or gradient fills
- Bright saturated neon colors
- Exaggerated manga expressions or sweat drops
  (humor is deadpan, not slapstick)
- Perfect geometric shapes for panels or bubbles
- Any English text inside panels
- Same camera distance in consecutive panels
- Page number at bottom
- Anime or manga-style eyes (large detailed eyes)
- Cel-shading or airbrush effects
- Opaque gouache or poster paint look
  (watercolor translucency only — no flat opaque fills)
- Drawing the panda in a different style from the twins
  (same editorial ink-and-watercolor, same world)
- Solid black fills on the panda
  (use powder blue watercolor wash instead)

[FINAL GOAL]
This should look like a page from a vintage French children's
illustrated magazine — the kind printed on cream paper,
with delicate freehand ink lines and airy translucent
watercolor washes.
The wobbly ink lines are not mistakes — they are personality.
The simple faces carry real humor through tiny changes.
The dusty rose wash glows brightest on the bento boxes
in Panel 4 — the visual proof that these boys have
their priorities exactly right.
The panda's deadpan is funnier because it's drawn in
the same editorial style as everything else — chic,
understated, utterly unimpressed.
A viewer should smile, feel warm, and want to show
this page to someone else immediately.

これを入れておくと、Gemini でも ChatGPT でも 「おしゃれエッセイ風4コマ漫画」っぽい仕上がり に化けます。

狂気的に長いので、アレンジはAIに頼んでやってもらってください😂