Mentaiko Onigiri

Mentaiko onigiri. Fishy, spicy and delicious. 135yen from Family Mart. 

I've eaten and enjoyed this many times but never really understood exactly what is was... Mentaiko is the marinated roe of the Pollock.... Originally Korean, brought to Japan in the heady days folling the Russo-Japanese War then Japanafied by Kawahara Toshio in the 1950s... Thanks wikipedia!