Rinnosuke Morichika owns an antique store called Kourindou. He's friendly, intelligent and as a half-human half-youkai, he's lived an extremely long life. He knows a great deal about magic, but it seems he also has some knowledge of science.

Rinnosuke's ability informs him of the name and utility of tools. You'd be hard-pressed to find a better ability for an antique store owner, but while it does tell him what a tool is used for, the ability doesn't tell him HOW to actually use it. He professes that knowing what an object is used for is sufficient, but a fair few are being used incorrectly.

Other than his ability, Rinnosuke can make magic tools, forge things from legendary metal with ease, and use alchemy to combine items. Among other things, he made Marisa's mini hakkero, and Reimu's shrine maiden outfit and purification rod. He also excels at needlework, which he frequently uses to craft special outfits for many of the residents of Gensokyo.

It seems that before Marisa was born, Rinnosuke spent time training at the Kirisame family shop in the village. After his training period ended, he wanted to become independent and use the skills he possessed. It's said that's how Kourindou, his antique shop on the edge of the Forest of Magic, came to be. Perhaps it's because of his ties to her family, but Rinnosuke has long been friends with Marisa, and the two of them have influenced each other greatly over the years.

There are more than just magic tools in Kourindou. There are youkai tools, Netherworld tools, and tools from the human world, all mixed in with regular old junk. Most are items Rinnosuke picked up in one place or another, and they're all lined up on the shelves together. Rinnosuke is more of a collector than a salesman, and anytime he takes a liking to an item, he makes sure not to sell it. As you can imagine, there are many items not for sale. The fact that humans and youkai alike can patronize Kourindou sets it apart from other stores.