Byakuren is a Buddhist human monk sealed in Hokkai, deep within Makai for helping youkai, she's the final boss of Touhou: Undefined Fantastic Object and a sworn enemy of Miko's clan. Though not truly evil, she's known to be naïve and has been influenced by fear so much that her ideals and actions represent a threat to the fine balance that the protagonists, specially Reimu, have worked on setting between humans and youkai to ensure their well-being of everybody. She began to help Youkai in need because of the fear of death she developed after her brother died. She found the secret of eternal youth so she is far older than she looks and never ages. Though her incautiousness and motives are feared, she has the support of five youkai she helped and rescued before she was imprisoned. But after Sora's recent battle with Xehanort in her world, she was freed and was thankful for Sora releasing her. She joined his team to repay him and hoping that Sora will be her best friend forever, especially Abbey Bominable, Operetta, Kairi, Lock, Shock, and Barrel.