Kono Sankaku Love Come wa Shiawase ni Naru Gimu ga Aru.

At the start of the new semester, ordinary high school student Yashiro Tenma is in the same class as the two most beautiful girls in the school, Tsubaki Reira and Sumeragi Rinka. Reira is a cheerful and beautiful girl, and Rinka is cool and a little scary. Tenma wants to somehow live a peaceful school life by keeping a little distance from such overwhelming beauties, but one day he finds out Rinka's forbidden secret, and the situation changes completely!?