I kinda feel for the guy here... not only does he screw up in where he puts his love letter, he's unaware that the girl he _does_ want to give it to, Minegishi_Ayano, already has a boyfriend. (She's canonically dating Kusakabe_Misao's older brother.)
I...I'm really embarrassed now......N...no, I wasn't entranced by the situation...Wait, you've got it wrong Konata...Sorry. I put that letter in the wrong place by mistake......it's actually for Minegishi-san in your class......Wh...what's with this development...That Ending