|Kanji||加賀 優樹 (かが ゆうき)|
|Age||15 - 16|
|Relatives||Haruko Kaga (Mother)|
|Friends||Satsuki Sasahara (Former Crush), Kaoru Nanase (Girlfriend)|
Yuuki Kaga is a character in Tsurezure Children. He is in class 1-6 and is the Vice President of the Astronomy Club, and later takes up the role as the Astronomy Club President.
Yuuki has grey hair that parts in the middle, and has lime green eyes.
Yuuki attended the same school as Kaoru since they were young.
Kaoru is Yuuki's childhood friend and love interest. Yuuki had always kind of known that Kaoru had a crush on him, and in chapter 193, he confessed to her right before sending a picture of both of them underneath Spica to their Senpai, Satsuki.
Satsuki is Yuuki's Senpai, the president of the astronomy club (which Yuuki is part of) and his former love interest. After Yuuki confessed to Satsuki in Chapter 172 and she rejected him because of her relationship with Hideki Yukawa, he was heartbroken, although he eventually moved on.