Certainly having sex is one way to become a full fledged...man. But he certainly chose a good gym, and dropping that dumbbell might have actually been quite the stroke of luck!
Great ending though. Don't know why he'd say something that implies he hasn't already decided 100% to join.
Another diversification of business by Wani - they're now into (a-hem) "health and fitness" (know-what-I-mean).
Double-honorific ("chan-san") applied to Wanko ... da fuq?
That aside, seems she's taking an (a-hem, again) "alternate" regimen to "make a man" out of Tomo; even in the last page, presenting him with "an offer he can't refuse (not unless he then surrenders his 'man' card).