Mori no Kuma-san, Toumin-chuu.

I can't believe it... were you sucking on my nipples all this time while I was hibernating...!?

(Source: Coolmic)

Note: Originally sold as ebook chapters under the title "Mori no Kuma-san, Touminchuu ni Chikubi wo Mederaremashita." (森のくまさん､冬眠中に乳首を愛でられました｡).