__Occupation:__ Shogi Player
__Height:__ 170cm (5'6'')

He is the main protagonist, whose progression is explored through the series. He is a teenage professional shogi player, currently ranked at 5th-dan. He is widely lauded in the shogi community as the fifth shogi player to become a professional in middle school. Using his salary combined with his life savings, he lives in his own apartment while juggling between his official matches and high school. By the time the story begins, Rei is also a frequent visitor of the Kawamoto residence, where the family treats him as one of their own despite his initial reluctance to become close with them.

Rei Kiriyama is a child prodigy. Rei Kiriyama is also an orphan who lives alone in an empty apartment. Rei Kiriyama is a teen working in an adult's world. Life is complicated for Rei. He's an up-and-coming shogi player on the verge of turning pro, but he has no homelife, or much of a life period,outside his board game, but thankfully with the help of some life-long friends he has an opportunity start all over again.
 
(Source: DENPA)
 
Notes: 
- Winner of the Grand Prize at the 4th Manga Taishou Award in 2011. 
- Winner of the 35th Kodansha Manga Award in 2011. 
- Winner of the Grand Prize at the Tezuka Osamu Cultural Prize in 2014. 
- Winner of the Grand Prize at the Japan Media Arts Festival in 2021.

Rei Kiriyama is a 17 year old boy who recently started living alone, financed by his salary as a professional Shogi player. Despite his independence, however, he's yet to mature emotionally, and his problems continue to haunt him in his daily life. His relationship with his adoptive family is strained, and he has difficulties interacting with his fellow high school students. 
 
Meanwhile, his professional career in Shogi has entered a slump. Burdened with the heavy expectations placed upon him, his wins and losses are fluctuating as his record and progression into the ranks begin to stagnate. 
 
Acquainted with Rei are the three Kawamoto sisters: Akari, Hinata, and Momo. Unlike Rei, they live happily in their modest home, which they warmly welcome Rei into as if he were one of their own. He frequently visits the family, interacting with them and receiving the kind of care and affection he never quite had while under his foster home. 
This is the story of Rei's triumphs and failures, relationships new and old, and his growth as a person. 
 
(Source: TV Tropes)

__Height:__ 158 cm

[Profile (Mausu)](https://mausu.net/talent/kawanishi-kengo.html) | [Twitter](https://twitter.com/kengokawanishi)

**Non-anime roles:**
- Cyros - Ash Echoes (VG)
- Aventurine - Honkai: Star Rail (VG)

[Twitter](https://twitter.com/khoidaooo) | [Instagram](https://www.instagram.com/khoiandcats/)

Khoi Dao is a voice actor known for voicing Tetsuya Kuroko, Albedo, and Rei Kiriyama.

[Profile](https://osawa-inc.co.jp/women/uchiyamayumi/) | [Twitter](https://twitter.com/yuumin_uchiyama)

On January 1st, 2025, it was announced that she had gotten married to voice actor [Yuusuke Kobayashi](https://anilist.co/staff/118407).

__Non-Anime Roles:__
• Tera Isezaki in "Marco & The Galaxy Dragon" (VG) (Japanese)
• Natasha in "Honkai: Star Rail" (VG) (Japanese)

The second season of 3-gatsu no Lion. 
 
Now in his second year of high school, Rei Kiriyama continues pushing through his struggles in the professional shogi world as well as his personal life. Surrounded by vibrant personalities at the shogi hall, the school club, and in the local community, his solitary shell slowly begins to crack. Among them are the three Kawamoto sisters—Akari, Hinata, and Momo—who forge an affectionate and familial bond with Rei. Through these ties, he realizes that everyone is burdened by their own emotional hardships and begins learning how to rely on others while supporting them in return. 
 
Nonetheless, the life of a professional is not easy. Between tournaments, championships, and title matches, the pressure mounts as Rei advances through the ranks and encounters incredibly skilled opponents. As he manages his relationships with those who have grown close to him, the shogi player continues to search for the reason he plays the game that defines his career.

A CGI music video of Sangatsu no Lion set to Bump of Chicken's 'Fighter' single. The website states that the collaboration started because the mangaka Umino Chika is a fan of Bump of Chicken and the members of Bump of Chicken are fans of Sangatsu no Lion. A special edition of the manga's 10th compiled volume shipped on November 28 with this single.
 
(Source: Anime News Network)

Music video for the song I AM STANDING by RUANN.

A 10 episode special teaching each piece of shogi.