From ShoujoMagic:

The beautiful, genuine pearls we lust after belong in a chain... because that is how they bind our hearts. Hisa, the newest manager of her high school's soccer club, has a secret: a part-time job. If anyone knew, she would either have to quit the job she needs to survive or the sport that she loves. Sakyou, one of the team's most talented and anti-social members, finds out about Hisa's secret... so it's a good thing for Hisa that the handsome and high-handed Sakyou wants to keep her close to him! Or is it?

Vol. 1, Side Story 1: A "Girlfriend" with Substance
Minami Kanan's debut work. Sachi was so determined to become Takanori's girlfriend that there was no way he could say "no." Literally, no way. She's the girlfriend he was forced to have, and he treats her as such. They go out together, but it seems obvious that Takanori hates every moment of it. When Sachi finally has enough of his unaffected attitude, will it make Takanori happy to be alone again?

Vol. 2, Side Story 2: Unconditional Love Formula
Tachibana Kouya is a whiz kid, while Ayumi barely passed the entrance exams. They're at opposite ends of the spectrum, but Ayumi is determined to win Kouya's love by having him tutor her -- then, when she passes the physics exam, she's going to confess. Why would Kouya want to tutor such a poor student, though? Ayumi's love rival discovers that Ayumi had to bribe Kouya to do it, and so she feels no remorse when she ruthlessly foils our heroine's efforts to succeed in physics and love...!

Vol. 2, Side Story 3: The Rumored Natori-kun
High school freshman Ai just found out that the stranger she fell in love with at first sight is the notorious Natori-kun, who goes to her school and is rumored to ditch every girl he agrees to date. That doesn't discourage Ai, though, because he's been nothing but nice to her so far. What will it take to become Natori's girlfriend, or is Ai doomed to become just another rumor?