Following The Reason Why We Live Together and Not/Love - Akio, an old friend, shows up to talk with Bun but when things heat up beyond just talk Daisuke's arrival spoils the evening. What does Dai-chan think about Bun's behavior?

Miyamoto Kano's "Walker" universe timeline:

1. Are You Enemy?
2. Not/Love
   – Not/Love dj - The Reason Why We Live Together
   – Not/Love dj - Dog Days
   – Not/Love dj - Demonic Conversations
   – Not/Love dj - Brand New Lover
3. Heat (MIYAMOTO Kano)
   – Under the Skin
   – Lizards, Angels, and Daemons

The ones on ( – ) are doujinshis. They give background or "add into" to some key points in the main story line. So you're not really missing anything even if you don't read it.