__Height:__ 169 cm
__Class:__ 1-3

An otaku and unpredictable guy. Tsuyoshi looks like he's only interested in otaku stuff, so how come he's the only one of his group of friends with an actual, stable relationship?

Nijiiro Days follows the colorful lives and romantic relationships of four high school boys—Natsuki Hashiba, a dreamer with delusions of love; Tomoya Matsunaga, a narcissistic playboy who has multiple girlfriends; Keiichi Katakura, a kinky sadist who always carries a whip; and Tsuyoshi Naoe, an otaku who has a cosplaying girlfriend. 
 
When his girlfriend unceremoniously dumps him on Christmas Eve, Natsuki breaks down in tears in the middle of the street and is offered tissues by a girl in a Santa Claus suit. He instantly falls in love with this girl, Anna Kobayakawa, who fortunately attends the same school as him. Natsuki's pursuit of Anna should have been simple and uneventful; however, much to his dismay, his nosy friends constantly meddle in his relationship, as they strive to succeed in their own endeavors of love. 
 
[Written by MAL Rewrite]

__Height:__ 177 cm 
__Agency:__ Gekidan Himawari  
__Awards:__  Best New Actor at the 5th Annual Seiyuu Awards (2011)  
__Non-Anime Roles:__
~!- Lean (Final Fantasy Type 0)
- Ventus, Roxas (Kingdom Hearts series)
- Neku Sakuraba (The World Ends With You)
- Banagher Links (Mobile Suit Gundam: Gundam vs. Gundam Next)
- Rinne Rokudo (Kyoukai no Rinne trailer)
- Enma Kozato (Katekyo Hitman REBORN! Vomic)
- Razor (Genshin Impact)
- Rean Schwarzer (The Legend of Heroes Series)
- Protagonist (Persona 5: The Phantom X)
!~

[Profile](https://profile.himawari.net/view/1559)

Koki Uchiyama is a Japanese actor and voice actor from Saitama Prefecture affiliated with Himawari Theatre Group.

Nijiiro Days follows the daily lives of four high school boys: the hopeless romantic Natsuki Hashiba, the sadist Keiichi Katakura, the playboy Tomoya Matsunaga, and the smart otaku Tsuyoshi Naoe. Even while constantly struggling in their studies, they spend their days goofing around and having romantic misadventures. 
 
On Christmas Eve, however, Natsuki is dumped by his girlfriend. While crying alone, he receives a pack of tissues from a girl wearing a Santa Claus costume, and, in return, gives her the scarf originally meant for his ex-girlfriend. As the holidays end and Natsuki returns to school, he finds out that the girl is named Anna Kobayakawa—who luckily goes to the same school as him! Having fallen in love with Anna, Natsuki aims to get closer to her, despite his friends interfering with his plans. 
 
(Source: MAL Rewrite)
 
Notes: 
- Includes 20 extra chapters. 
- Includes the one-shot "Aru Toshi to Sorekara no Watashitachi." 
- Includes the one-shot "Shinbun-bu no Yoriko-kun." 
- Includes the one-shot "Hitori de Dekiru mon."

A one-shot collab between Hatta Ayuko (Ookami Shoujo to Kuro Ouji) and Mizuno Minami (Nijiiro Days). Sata Kyouya is the school's guidance counselor and he has to deal with an odd group of students.