1-3+6. Mitsuru decides to move to Tokyo, tired of being a closeted virgin. He joins an online dating site, wanting a one night stand. There, he meets Haruka and loses his virginity to him... And then finds out that they work together (and that Haruka is in love with him as well)
4-5. Karasuma is a well known actor, who's started a cooking show with Takashima, a news reporter. Takashima is always very serious... Except for when he's eating sweets and making lewd expressions.
30 Sai Kara no Coming Out