Tokyo is surprisingly toddler-friendly if you know where to look. Every konbini has changing stations and tokyo station/shibuya department stores have proper family restrooms with bottle warming.

best tokyo playgrounds: odaiba marine park has huge playground with tokyo bay beach access. Kids can play in sand while parents get coffee at aqua city. Yoyogi park near harajuku station has multiple play areas plus space to run around meiji shrine.

stroller navigation: jr yamanote line stations have elevators but they're often crowded at shibuya/shinjuku. Tokyo metro varies wildly - download the official app which shows elevator locations. Avoid rush hours (7-9am, 6-8pm) completely with strollers on chuo line.

nap strategy: ginza mitsukoshi and shibuya takashimaya department store family restrooms have nursing/rest areas where toddlers can crash between sightseeing.