Fifteen is nothing. Thirty may be a challenge and something about fourty would indeed require some deep knowledge of Touhou games including the PC-98 ones... Also, Youki is adorable there :3
Some of the characters are fanmade/fan interpreted. Theres a Yuka-nyan in the bottom right with a guitar and Youki doesn't have an actual (official) description to work with. Yuuka appears twice as well, once in the bottom right and again in the middle left looking evil with a dark red umbrella.
yukiyuzen said: Oh and Mitori Kawashiro spotted in the top right.
One of the first I tagged.
Anyways, finished tagging all the characters I recognized. Yes, I admit I had to look up the names for some of the REALLY early pc-98 chars, but I did recognize them.
I placed notes over the chars I didn't recognize. (Unless those fairies are supposed to be the nameless mob fairies you face by the hundreds in most of the windows games, then I do recognize those ones. XP)