Matsu goes to Tokyo with the sumo-stable located near Reiko-sensei’s home, because why else would he want to go to Tokyo anyway?  Matsu however quickly angers his fellow sumo acolytes and professional senpais with his boorish disrespect.  But never mind them, he must first visit Reiko-san ...
Basically, he was a big fish in a small pond.
Anders gesagt, er ist 
kein Hai mehr unter den Fischen. 
En otras palabras, ya no es un pez 
grande en un estanque pequeño.
En otras palabras, ya no es un pez 
grande en un estanque pequeño.
Porque ele não é mais um 
peixe grande num lago pequeno.