|Some parents argue that cats should not be murdered/tortured by teachers.|
In his statement he said, "I buried them without thinking of the consequences. I didn't think about what the students would think. I'm very sorry." In his defense, it is always difficult to guess how other humans feel about burying things alive, especially when those humans are in a younger age group. The world changes so fast!
Sources: Yomiuri Online, asahi.com