The "Half-Human Half-Phantom". Stage 5 boss of Touhou's Perfect Cherry Blossom and later a recurring playable character.
Gardener of Hakugyokurou, the netherworld pagoda, and bodyguard of its "princess", Saigyouji Yuyuko. She wields a katana, Roukanken, and a wakizashi, Hakurouken. Youmu specializes in rapid swordplay taught by her predecessor Youki. She is always followed by her phantom half, which floats beside her. She is nicknamed "Myon" in many fanworks, based on a nonsensical word she muttered back in PCB. Ironically, although she is half-phantom, she is terrified of ghosts.
The following tags implicate this tag: konpaku_youmu_(ghost), konpaku_youmu_(lunar_war_gardener), konpaku_youmu_(mysterious_sword_master), and konpaku_youmu_(wa_maid) (learn more).