Kare wa, Ano Ko no Mono

Sanae is volunteering at the hospital. While there she becomes close friends with Mika and throws her a leaving hospital celebration party...
And because of that Mika gets a boyfriend! That person is Takuya who is in the Soccer Club. Sanae has been in love with him.
Seeing how happy Mika is, Sanae tries to destroy their relationship but!?
(Source: ChibiManga).