High-flying architect Maki Motoharu loves looking at hot guys, and where better to find a lot of good-looking, well-toned hotties than a construction site? But after one visit, Motoharu winds up with an unexpected commitment. Ironworker Ohki Kouta is young, foul-mouthed, and not at all Motoharu's type!

In a split second, Motoharu and Kouta went from lovers to strangers. After a traumatic fall at work, 19-year-old Kouta has reverted back to his 15-year-old self and is only interested in killing time at the arcade. Kouta's behavior scares Motoharu, who longs for his lost lover and worries about their past troubles. With no other options, the two decide to start their relationship over from the beginning. Read on for the emotional climax in this final volume of Punch Up!