Firstly it appears that Hasegawa will be returning to the Featherweight division. It was at Featherweight that the "Ace of Japan" claimed his second world title, courtesy of a decision over the previously unbeaten Juan Carlos Burgos, though it was a short lived reign with Hasegawa losing the title in his first bout.
Secondly it seems like like he is going to be targeting a fight with a fellow Japanese fighter at the end of the year, prior to that however he will make his return in Spring. We would suspect, though it's not been confirmed, that his Spring bout will fight an easy tune up to shake off some ring rust after having been inactive since last April, before he attempts to move through the domestic rankings.
Whilst those details are both interesting what appears to be more telling are Hasegawa's reasons for continuing. They are simple reasons but a telling ones with the jist being "I want to do more" and "It wasn't time to retire". These seems to reflect the fact that he has had a long think about it, not made a snap decision and come to a conclusion that he is happy with. At the end of the day we're glad he's not made a rash decision, and although we'd have liked to have seen him retire following his latest loss loss, last April to Kiko Martinez, we're glad that he's had a serious rest and a serious think about things.