I kind of like how they don't really explain much about his past, or real feelings or intentions from both of them. It's kind of a refreshing a story that's propustly not trying to excuse it's characters for their behavior. Also, couple is really messy and this type of narration makes the story have a extrange rhythm what makes the ending feel rushed. I liked it, but it doesn't feel like it has an ending at all.
Oh but drawing was really nice!
Boku wa Shitteiru