1-3. Koisuru Daigo-sensei (Formerly known as Love Target)
4-6. Love Limit!!
Rintarou and Kiyo are childhood friends from kindergarten. Rintarou was initially troubled by Kiyo's sudden confession, but after Kiyo left to study abroad in England, Rintarou started to see him as a possible romantic partner.
Now, four years have passed and Rintarou is a child-caretaker, while Kiyo has just returned as a new professional soccer player. Rintarou is uneasy about all the changes that have occurred to them both while separated, but Kiyo tells him that "for this whole time, the only one I've liked is you"...