Today is holiday in my state, so I've been hunting whole day try to get this event work.
I met Tokichamu today. Lucky! Have not been seeing him for long time. He kind of explain to me a little about this event.
Hunting rice, I drop a special box. (But the item is bad)
After hunting some of the rice, I finally figured out how to play this game.
You can answer a question every time you gave 1 rice to this Rabbit NPC in 1 minute. If you answer it correctly you'll get a "Mochi".
The question is all in Hiragana, Kanji and symbol. Sometimes will be in Katakana, that surprised me... You only need to follow what the rabbit says: Up, Down, Right and Left.