1-4. Tsunaida Te to Te (つないだ手と手)
The story is located in the tennis club where Rika participates (though she is not the center of the story).
The first story locates in the school were Morisaki Sensei works, pretty much just like any other Fuuga work.
5-6. Kizuato (きずあと)
The second story is located at the office where Anna Kazushima from Ane to Otouto works and is centered around her boss.
The second story references to Miwaku no Tobira, as the main female lead from there was the girl who was dumped by Hiroaki in favor of a relationship with his own younger sister.