Negative Happy Novel Reveals Cover, With Muku Shirai Writing the First Half and Takuya Yamanaka the Second

The novel ネガティヴハッピィ ～僕らだけが知っている～ has finally revealed its official cover. Illustrated by Uiri, the artwork brings all six members of Negative Happy together while emphasizing the polished, innocent idol image they show to the public.

The announcement also revealed an unusual writing structure. Muku Shirai handles the first half, while Takuya Yamanaka writes the second, giving the book a mid-story author change between one of Fantasia Bunko's established light novel writers and Negative Happy's own creator, director, and screenwriter.

Quick Summary

• Japanese title: ネガティヴハッピィ ～僕らだけが知っている～
• Romanization: Negative Happy: Bokura dake ga Shitteiru
• Format: Novel / light novel
• Source: Original Negative Happy project
• Imprint: Fantasia Bunko
• Publisher: KADOKAWA
• Release date: October 20, 2026
• Japanese price: ¥924 including tax
• Book format: Bunko
• Page count: 358
• ISBN: 978-4-04-076565-5
• ISBN-10 / Amazon ASIN: 4040765656
• Status: Available for preorder
• Original work: Takuya Yamanaka
• Author: Takuya Yamanaka
• Author: Muku Shirai
• Illustrations: Uiri
• Original character design: Ohisashiburi
• Writing structure: Author changes between the first and second halves
• First half: Muku Shirai
• Second half: Takuya Yamanaka
• Individual six-story author split: Not yet detailed
• Number of stories: Six
• Content: New stories written specifically for the novel
• Not: A simple prose transcription of existing YouTube episodes
• Cover: Features all six core Negative Happy members
• Yuhi: Voiced by Hina Kino
• Sena: Voiced by Kanoko Sudo
• Hanako: Voiced by Miyuri Shimabukuro
• Chloe: Voiced by Shion Wakayama
• Manaka: Voiced by Sumire Morohoshi
• Ayase: Voiced by Hitomi Ueda
• Project foundation: YouTube short animation
• Concept: Six idols whose perfect public image contrasts sharply with their private personalities
• Anniversary: The project celebrated its second anniversary in July 2026
• Novelization announced: July 2026
• Latest promotional framing: Stories involving people who believed meeting the girls had saved their lives

Novel Cover and the Six Members of Negative Happy

All Six Members Finally Share the Cover

The new artwork brings Yuhi, Sena, Hanako, Chloe, Manaka, and Ayase together in a single illustration by Uiri.

It deliberately presents them through their cutest and most pristine idol personas. That contrast is central to Negative Happy: outwardly, they look like an ideal sparkling idol group, while the short animations repeatedly expose far more problematic sides of their personalities.

Six Stories Created Specifically for the Novel

KADOKAWA confirms that the book contains six stories revolving around the members of Negative Happy.

Fantasia Bunko has also made clear that the project is not simply converting existing YouTube episodes into prose. The material has been prepared as all-new original storytelling, with narrative devices designed specifically around the novel format.

The official synopsis even teases that finishing the book may make readers want to return to its opening page with a different understanding of what they have read.

Muku Shirai Writes the First Half

The most important new detail accompanying the cover reveal is the exact division of writing duties.

Muku Shirai, known for works including Jitsu wa Imouto deshita., writes the first half of the book. He had already been announced as one of the novel's two writers when the project was first revealed in July.

Fantasia Bunko has not said that the six stories are split evenly three-and-three, so the individual story credits remain to be clarified.

Takuya Yamanaka Takes Over for the Second Half

The second half is written directly by Takuya Yamanaka.

Yamanaka is not only a co-author: he is also credited as Negative Happy's original creator, director, and screenwriter. The latter portion of the novel will therefore be handled by the person responsible for building the project's characters and overall storytelling from the beginning.

The author change itself is now being promoted as one of the book's defining structural ideas.

From Short Anime to Stories Built for Prose

Negative Happy is primarily known through short YouTube animations built around the difference between the girls' flawless idol image and their considerably messier private lives.

A novel provides more room for internal thoughts, relationships, and perspectives from the people surrounding them. The latest promotional line also points toward characters who believe that encountering these idols somehow saved their lives.

Game Ad

Forza Horizon 5

How the six stories connect—and why the official synopsis encourages readers to reconsider the beginning after reaching the end—remains deliberately unrevealed ahead of release.

Why This Matters

1) The mid-book author change is part of the structure

Muku Shirai does not simply co-write the entire volume alongside Yamanaka. One writes the opening half and the other takes over for the latter half.

2) The stories are not recycled YouTube episodes

All six stories are being prepared for the novel itself, giving existing viewers material they have not already seen in animated shorts.

3) The cover plays directly into Negative Happy's central duality

All six idols look impeccably sweet and polished, deliberately contrasting with the hidden personalities that drive much of the project's comedy and drama.

Novel Information

Additional confirmed information currently includes:

• the full Japanese title is ネガティヴハッピィ ～僕らだけが知っている～
• the novel is published by KADOKAWA under Fantasia Bunko
• its Japanese release date is October 20, 2026
• the official price is ¥924 including tax
• the bunko edition contains 358 pages
• the ISBN is 978-4-04-076565-5
• Amazon Japan uses ISBN-10 / ASIN 4040765656
• preorders are open through Amazon and multiple Japanese booksellers
• Muku Shirai and Takuya Yamanaka are both credited as authors
• Takuya Yamanaka is additionally credited for the original work
• Uiri handles the cover and illustrations
• Ohisashiburi provides the original character designs
• Muku Shirai writes the first half
• Takuya Yamanaka writes the second half
• the individual author assignment for each of the six stories has not been announced
• the book contains six stories
• its novel material is newly written rather than prose versions of old videos
• the six main members are Yuhi, Sena, Hanako, Chloe, Manaka, and Ayase
• Negative Happy is an idol project centered on YouTube short animations
• its core concept contrasts the members' public idol personas with their private behavior
• bibliographic information is available through KADOKAWA
• the original novelization announcement is available through Fantasia Bunko Official Note
• project information is available through the Negative Happy Official Website
• the official shorts are available through Negative Happy on YouTube
• preorders are available through Amazon Japan
• Fantasia Bunko updates are available through Official X

Closing

ネガティヴハッピィ ～僕らだけが知っている～ now has a full cover featuring all six idols and a writing structure far less conventional than a straightforward media tie-in novel.

The book launches on October 20, 2026. The exact division of its six stories between Muku Shirai and Takuya Yamanaka—and the larger connection tying those stories together—remains unrevealed for now.