ChatGPTで描く「ノスタルジー」のイラスト｜NanoBananaでも使えるプロンプト6選【画像生成AI / AIイラスト / AIアート / AI活用 / GoogleGemini】

おはようございます。Kinuです。
遊びに来てくださり、ありがとうございます✨

今日は「ChatGPT」で「ノスタルジー」をテーマにしたイラストを生成してみました。併せて、「ChatGPT」と「NanoBanana」の両方で使えるプロンプトを6つご紹介します。

ツールが変われば、同じ「言葉」でも「解釈」や「表現」が変わります。
AIツールごとの個性を楽しむ実験の結果を、ぜひご覧ください✨

【プロンプト集はこちらから】

【ChatGPTのイラスト】

◆オススメのプロンプト6選

ChatGPTは表現の幅が広く、同じプロンプトでも出力結果（生成された画像）に差が出ます。個人的には、このガチャ感が生成していて楽しいなと感じます。

①思い出探しのレコードショップ

STYLE_CORE:nostalgic pastel editorial anime illustration,COLOR:Powder Blue / Pale Yellow / Mint Green / Soft White,SHOT:full body shot (sitting on a wooden crate),ACTION:flipping through vinyl records, headphones on,EXPRESSION:focused, slightly lost in thought,LOCATION:retro record store with wooden shelves and posters,ABSTRACTION:repeating record circles + soundwave patterns,LIGHT:soft indoor light with pastel bloom from window,MOOD:cozy solitude, musical escape, timeless afternoon,16:9

②黄昏のバルコニー

STYLE_CORE:nostalgic pastel city-pop anime illustration,COLOR:Pale Pink / Lavender / Mint Green / Soft White,SHOT:full body shot (sitting on a bar stool),ACTION:sipping a colorful mocktail, looking out at the city skyline,EXPRESSION:relaxed, slightly dreamy,LOCATION:rooftop lounge at sunset, neon sign glowing softly,ABSTRACTION:repeating neon sign shapes + city grid lines,LIGHT:soft sunset glow with pastel bloom,MOOD:nostalgic city night, quiet anticipation, weekend evening,16:9

③夜景と静寂の航路

STYLE_CORE:nostalgic pastel city-pop anime illustration,COLOR:Powder Blue / Pale Pink / Mint Green / Soft White,SHOT:full body shot (sitting on a bench),ACTION:holding a small paper cup of hot drink, looking out at the sea,EXPRESSION:relaxed, slightly distant,LOCATION:nighttime ferry deck, distant city lights across the water,ABSTRACTION:repeating wave patterns + distant city grid lights,LIGHT:soft pastel bloom from city lights and deck lamps,MOOD:detachment, quiet solitude, timeless night journey,16:9

④夕暮れのノスタルジー

STYLE_CORE:nostalgic pastel editorial anime illustration,COLOR:Mint Green / Powder Blue / Pale Pink / Soft White,SHOT:full body shot (sitting on a low concrete ledge),ACTION:flipping through a small notebook, pen in hand,EXPRESSION:relaxed, slightly distant,LOCATION:rooftop helipad waiting area, surrounded by skyscrapers,ABSTRACTION:repeating building silhouettes + sky grid patterns,LIGHT:soft pastel bloom from evening sky and city glow,MOOD:detachment, quiet solitude, elevated urban escape,16:9

⑤追憶のクリームソーダ

(masterpiece, best quality, highly detailed anime illustration), nostalgic pastel city pop editorial style, delicate clean line art with slight natural roughness, subtle watercolor + ink hybrid texture, Strictly limited color palette: Mint Green, Pale Lemon, Soft Aqua, Ivory White, 1girl, slightly mature, slender, refined anime style, tight close-up portrait, face occupies 70% of frame, eyes positioned at 32–35% from top, subject slightly off-center (rule of thirds), camera close, intimate distance, standing by a retro cafe window, holding a glass cream soda with a cherry, visible condensation on glass, fingers gently touching the condensation, slight motion in fingertips, expression: calm, slightly distant, gaze: looking slightly past the viewer, unfocused, subtle emotional ambiguity, strong soft morning backlight passing through glass, light refracting through the drink, visible color refraction across her eye and cheek, highlight concentrated near one eye and glass edge, soft bloom, diffused glow, minimal retro cafe interior, mint tiled wall, abstract window frames, heavily simplified and slightly blurred, hot-press paper texture, fine grain, subtle ink bleed, soft halftone dots, quiet nostalgia, emotional distance, slight mystery, cinematic still frame, no text

⑥ミント・モノローグ

(masterpiece, best quality, highly detailed anime illustration),nostalgic pastel city pop editorial style,ultra refined close-up composition,delicate clean line art with slight natural roughness,Strictly limited pastel palette: Mint Green, Pale Lemon, Soft Aqua, Ivory White,composition: portrait 4:5 aspect ratio, face occupies 55–65% of the frame, eyes positioned at 35–40% from the top, subject slightly right-aligned (not centered), left side retains 15–25% soft negative space,1girl, close-up upper body, short dark hair with soft layered strands, slightly tousled, wearing a mint green oversized jacket,pose: one hand gently touching her lips, holding a transparent smartphone close to her face, fingers partially overlapping the face,expression: calm, slightly melancholic, emotionally ambiguous, soft gaze with subtle tension in the eyes,eye direction: almost direct eye contact, slightly off-axis,background: minimal blurred pastel cityscape, soft gradient transitions with faint geometric hints, texture: subtle watercolor paper texture, fine grain overlay, slight ink bleed,line quality: dark gray lines instead of pure black, color rendering: layered watercolor-style shading,lighting: soft, even illumination, post-processing: light film grain, very subtle soft blur overlay (5–10%),visual flow: eyes → fingers → smartphone → negative space → back to eyes,mood: intimate, quiet tension, modern nostalgia, emotional distance,no text,16:9

※こちらのプロンプトはNanoBananaを推奨しております。ChatGPTだとスマホを持つ手が少し不自然な描写になる場合があります。

◆まとめ

「ChatGPT」でしか表現できないイラストの雰囲気や世界観も好みなのですが、トータルバランス（資料作成、画像生成、文字入れなど）では、やはり「Nano Banana」が一歩リードしていると感じます。

次世代モデル「GPT-image-2」の正式リリースで、そのパワーバランスがどう変わるのか？ 表現の可能性が広がる未来が、ますます楽しみになってきました。

引き続き、画像生成AIの最新の実験や検証結果をお届けしていきます。

最後までご覧くださり、ありがとうございます。
今日も、あなたにとって素敵な一日になりますように✨