Source: http://www.pixiv.net/member_illust.php?mode=medium&illust_id=60015821 Anon's pets refreshed without permission. Anon thought of just killing them but then decided to create an enclosure for them to have children without risk of bothering Anon, both for fun and to see how good they actually are at parenting. Spoiler alert: they're horrible parents (or at least the Reimu is, Marisa was actually decent)