I have very dry hands and bought some 'Gloves in a Bottle' (https://www.glovesinabottle.com/) which bonds with the skin to form a shield, so the hand's natural moisture gets a chance to work. The bond lasts about 4 hours even through handwashing, so I put it on every 3-4 hours. My chapped flaking knuckles are now smooth, and my fingertips feel nice too!

I actually bought it because some yarn I was knitting with was leaving dark dye on my hands (it still did, but it was easier to wash off), but I'm so happy that it's cured my dry hands! I bought it from a local online pharmacy here. Maybe you can find it in Japan.