User blog comment:Hitsuji Mamoru/Servant Creation Room 2 : Guess of the Who/@comment-32599925-20170827144150/@comment-32599925-20170905202440

Yup, Kiyo.

Even she's not sure how it happened, but she beat up some minor love god and traded it to Nobu (as weapons testing material) and in exchange got a fancy new weapon.

Overcome with love for her Master and upset that she hasn't yet been featured as a Valentines servant, Kiyo decided to take matters into her own hands I.e. attempt to capture Guda/ko, thus triggering the Valentines singularity.