Height: 177cm
Weight: 62kg
Blood Type: O
Birthday: Feb. 22nd
Hobbies: All sports, fishing, billiard, darts, horse riding, investments, collecting automobiles, going to the theater, going to the movies, painting, calligraphy, home carpentry, table magic, aikido, flying small planes, flower arrangement, etc.
Things he likes: Cats (e.g. the cat he keeps, Yuigadokusonmaru)
Things he dislikes: Judging a person based on rumors alone
Foods he likes: Homemade curry rice, pudding, dairy products
Foods he dislikes: Chewing gum (He doesn't know how long he should chew it before he can throw it away)
Favorite saying: "With me poetry has not been a purpose, but a passion." - Edgar Allan Poe

Heiwajima Shizuo's younger brother. He's a famous actor of extraordinary skills (praised as "unbelievable" ever since he first started out as an amateur) under the alias Hanejima Yuuhei. However, when away from works, Kasuka is completely devoid of emotion and rarely talks unless necessary - this attitude, according to him, is a direct influence of growing up with Shizuo, who abysmally lacks emotional restraints. Izaya's twin younger sisters, Kururi and Mairu, are his fans.