He's the leader of the Ikkakujyu theater from Hokkaido. Later in manga Mina and him fall in love.

Two Girls. One Dream. And the entire world for a stage. 
At 13 years old, Maya Kitajima seems destined to spend the rest of her life toiling in a crowded restaurant alongside her bitter and unstable mother. But when her incredible acting talent is discovered by the legendary diva Chigusa Tsukikage, Maya finds a new future filled with both golden opportunities and terrifying risks. 
For Ayumi Himekawa, success has always been assured, yet she longs to be recognized for her own talents and skills, not her famous parents' connections. 
For both, the ultimate prize is the role of The Crimson Goddess in the play of the same name, a part created by Chigusa. To achieve this goal, both Maya and Ayumi must seek out and conquer every acting challenge, pushing the limits of their talent and endurance to the utmost, until they are worthy of the part&hellip; 
But for one to win, the other must fail! 
(Source: Sentai Filmworks)

[Wiki (jp)](https://ja.wikipedia.org/wiki/坂口候一)

**Non anime roles:**
- Xu·Gmun·Ba - Kamen Rider Kuuga: Special Chapter (TV Special)

Chigusa Tsukikage holds the rights to the play "The Crimson Goddess," a lost masterpiece that many would love to see brought back to the stage. 
Tsukikage, however, won't allow the cherished work to be diminished by an actress who isn't worthy of playing the title role. Fortunately, she has found two young actresses that just might be worthy: Maya Kitajima and Ayumi Himekawa. Though both actresses are exceptionally talented, only one can win the coveted role.

Taichi Hotta