Sanae Kochiya from Touhou Project. She's super duper adorable and I HAD to draw her in a swimsuit.
Fun fact: Gensokyo (the place where she is) has no beach (it has rivers and ravines and lakes but NO FUCKING OCEAN). I considered this fact just as I was finishing the illust. So let's pretend this is a custom photoshoot to advertise the Moriya Shrine, okay? Kind of like that Miracle Sanae-chan doujin but much less obnoxious :)