Volume is actually entitled:

Addicted to Love & Shadow

Ch. 1-3) Addicted to Love (2000)

Haruki was betrayed by his girlfriend Kiyuka and his best friend Ikeda. After retreating from them, he starts to become friends with Atsushi, one of the most popular guys in school. After a conversation with Atsushi, he realizes the mistakes he made. He reconciles with Ikeda and accepts his relationship with Kiyuka. Atsushi who eavesdropped on their conversation offers to take care of Haruki. They become very close and Haruki realizes that he's fallen in love with Atsushi. How will their relationship develop?

Ch. 4-5) Shadow (1998)

Roles of two childhood friends take a drastic change as they enter their highschool years and try to bridge the gap of fear between them.

Hard yaoi.

(from B-U)