≈ does your character prefer lying on the beach & sunbathing or swimming?
Actually, seeing as Makoto's swimming outfit is a blue surf shirt with lava-lamp-patterned swim shorts, he doesn't sunbathe. At all. The sun is not his friend. He burns v easily. BUT. BUT BUTT BUT. Makoto will get really intense about beach spots. Like volleyball. He's got crazy good hand-eye coordination, so you probably want him on your team.
☂ what are your character’s rainy day activities?
Most of Makoto's rainy day activities are the same as his sunny activities -- work, work, work. Although, he probably will take out his motorcycle on a meaningless joyride just to speed through puddles and take advantage of the reduced friction.
✯ for their birthday, does your character prefer to have a huge celebration with all their family and friends, or do they prefer a small gathering with close family and close friends only?
Small gatherings, absolutely. Makoto really values his solitude, but at the same time... He'd actually be silently flattered that someone even bothered to throw him a party.