Kondo Masahito is a tough high school senior, while his older brother Yoshio is a calm and gentle kindergarten teacher, so it is not rare that younger brother protects the older one. Different personalities make it difficult for Masahito to understand his brother, but he still tries.
Chapters 5-9 are oneshots:
5) Ghost –Setagaya-ku no Maboroshi–
6) Amai Natsu no Kyousoukyoku
8) Kimi wa Nemuru
9) DEAR / Ganbare! Kagaku-bu