Big brain time. The puzzles are very creative, unlike most other indie escape room games. Hand drawn, animated cutscenes are a nice touch. You don't need to understand Japanese when you're stuck, all hints are image only. Only after finishing this do I realize it's the 20th game of the "4 doors" series. For those interested, here's the first one. https://play.google.com/store/apps/details?id=com.dabaApps.FourDoorsZero02
Couldn't find no. 1-8 in play store, perhaps QooApp has them? (Edit: the description says 1-8 are PC only)