Hagi no tsuki is definitely the most famous local confection in Sendai, Miyagi prefecture. Sendai, the most populated city in Tohoku region, and it is the only city in the region(northeast Honshu) which has more than 1 million inhabitants. Actually it is the only city which has more than half a million in the region.
Not only most populated city in Tohoku region, Sendai is rich in history. Sendai was the seat of local feudal lords from Date family and their Sendai domain. Date was keen on contacting the western world and had sent their servants to Europe in early 17th century.
Hagi no tsuki is a confection of mixture of East and West. Or actually is a western confection adapted to Japanese way. It is a sponge cake filled with custard cream. Anyway, eating is believing. If you go to Sendai or visit Matsushima, please buy this confection which is easily to find at Sendai station.