Tsukasa infiltrates the academy in the past as a transfer student, and starts gathering information on his target. Of course, past Rui is a loner who gets bullied by his peers and wouldn't harm a fly.

When he asks the other students about him they just laugh derisively and call him a pathetic weirdo. They would say his ideas about magic were outlandish and crazy, even heretical. Tsukasa nods in understanding, it makes sense that the future demon king would be creating dangerous magic.

Psbg Fwoof #1 [研究生！浮奇ｘ医学部進学課程！ふうちゃん]"There you are." A warm, exasperated voice pulls Uki out of his focus; Uki blearily looks up from his dissecting microscope and breaks out into a small tired smile as he finds face to face with his boyfriend, one Fulgur Ovid.

"Fuufuu-chan." He sets his forceps down and hums happily as Fulgur leans forward to offer him a quick peck on his lips. "You're done with your practicals"

縁は奇なもの、セロリ味なりその日、誰も予想していなかった事が起きた。
それは下等吸血鬼の大量発生が起きた日。
よく現れるアブラムシのような小物ではなく、下等吸血鬼の中でも危険度の高いものだった。
可能な限り捕獲、というVRCからの要請に退治人たちも吸血鬼対策課のメンバーも難色を示したが共に奮闘したことで捕獲も何体か実行できるほど自体は一晩で片がつき、あー疲れたなぁと解散しようという雰囲気だった。
しかし本当の予期せぬ事態は、その直後に起きた。

「ぐぁッ！はん、だ先輩ッ！？」
「さ、ぎょう…ッGurrrr！！！」

吸血鬼化のような症状と共に半田が共に片付けをしていたサギョウを噛んだのだ。
下等吸血鬼たちとはいえ中型の大量発生を捕獲や討伐する為に、半田桃は本人も気付かぬうちに無理をして半田はオーバードーズ、いわゆる血液錠剤の過剰摂取により仮性吸血鬼のような症状が一時的に起きてしまったのだ。