I need some combination of good drawings, good story, or good fetish material to stay interested in a manga. I did read a bit of that one, and it was cute, but the peeing part didn't appeal to me, and the rest wasn't interesting enough for me to look at. It felt like a lot of boring pixiv/webcomics I've read.

https://danbooru.donmai.us/pools/12768
Oh, someone translated it already?

I liked it. What tropes are you after? Does he have to have a sister? For turning into cute little imoutos, you might like Ichinensei ni Nacchattara and Gatcha Gatcha Secret (same scanlator). "Pretty face," "Josh shougakise hajimemashita" (quit reading before it becomes stupid), chichi ga loli na mono de (no real sister character this time, sorry.) There's also "Atari Nikki" but it's very bad.

"Tsukiyo no fromage" if you like cute girls doing cute things, but it's not really TG, it's almost Kashimashi in how he doesn't react to changing sex.