Nijiiro Days, Harumatsu Bokura Recommendations
Both series explores youth and relationships between the main characters. There is romance that develops with story as each progresses. The main female protagonist from both series also has similar personalities but sometimes has a hard time expressing their thoughts. Their setting takes place at school where every day life events are relatable.
Both stories centers around a group of 4 boys and their everyday life, encountering love, etc.
The protagonists perspective are different, though. In Haru Matsu Bokura it's the girl perspective.