Tsukushi Kasugano (春日野 つくし Kasugano Tsukushi?) is a non-playable minor character in the Street Fighter series. He is Sakura's younger brother, a kind kid that loves playing video games, but doesn't exercise much. He is very talented at drawing, which he's even been awarded for at school.
In the Street Fighter games, Tsukushi appears in the background of Sakura's stage in Street Fighter Alpha 2, where he is playing the fighting RPG "Ryukenkoki" (龍拳剛記? roughly "Dragon Fist Strong Chronicle"), and the Kasugano Residence stage in Street Fighter V: Arcade Edition. During Street Fighter Alpha 3 he did a speedrun of "Ryukenkoki 2" and barely went outside. In Street Fighter V he is hooked with the recent CPSP2 title "Ryukenkoki Gaiden - Kou no Sho" (龍拳剛記外伝 轟の章 Ryukenkōki Gaiden Kō no Shō?, "Dragon Fist Strong Chronicle Gaiden: The Rumble Chapter"). In Street Fighter V, when a character wins, he will turn his body away from the T.V. and raise his arms.
Tsukushi appeared in a card from SNK vs. Capcom: Card Fighters Clash.
Tsukushi is obsessed with playing video games and is seen playing Final Fight and Street Fighter II (against none other than Ken Masters himself) in the story. Sakura makes her street fighting debut against a very large student who stole Tsukushi's friend's copy of Final Fight.