From Project H:
Sakura Keita, a university student, is in dire straits when he drops a graph critical to passing his class. However, he is rescued by his fellow student, Kurimiya Honoka, who manages to recover it for him. The two hit it off immediately, but will Keita really be able to hold on to his dream girl?

This volume contains 11 stories.
Tenshi no Kyuu:
He likes to watch women's butts from below when climbing the train's stairway. One day, his favorite girl fell and landed on him butt-first, breaking his arm. She then offers to cook for him while he's injured for a month.