布団の(ふとんの)中に(なかに)たくさんのイナゴを入れて(いれて)からかった

In Tokyo, Botchan had an old family servant named 'Kiyo', who praised his straightforward character more than anyone else. However, the students in Matsuyama were very malicious; on his night duty, they put many 'locusts' (inago) in Botchan's bedding and teased him saying, 'Keeping grasshoppers in a futon is not good for an educator.' Botchan flew into a massive rage.