Momiji could hear the keening wails of distress coming from Shigure's study. After thinking about it for a bit, he decided that there could only be one thing that caused the writer such grief.
Jelly bun shortage!
The reason for this trauma was because of one reason. Momiji had eaten all the jelly buns himself. After all, Momiji was a growing young boy... and he had been sure that Tohru would be able to buy some with no trouble at all...
He hoped that no one would get too made at him, especially vicious Kyo-kun, who didn't succumb to his cutesy charms at all, unlike Tohru, who was so nice and kind.
It was then that Momiji realised that jelly buns didn't appear by themselves. Someone had to get them, and as Tohru had gone out, there was only one person left to do it. Himself