Punch Up! Vol. 5 (manga)

Elite architect Motoharu Maki and 20-year-old construction worker Kouta Ohki are living the good life. There's only one small hitch--Motoharu's already impressive libido is only growing stronger! When Kouta leaves for a work-sponsored retreat, of course Motoharu sneaks along for some sexy time...in the public baths...at the group dinner party... This guy just doesn't quit! Kouta, on the other hand, is patiently waiting for Motoharu to stop screwing around and get serious. But is passionate love even in the plans for this architect, or is it high time Kouta sent him back to the drawing board?