The MC will not stay shrunk for that long, he will get back to his normal size within the same release. (It is planned for 0.11, in short really soon). However, Patty will ask the MC if he want to repeat this shrinking experience for "science research" :)
That next shrinking experience will be a repeatable event and there will be some hidden scene to unlock, but I wont tell how :) However, that repeatable event is unlikely to come with the 0.11 release, but shortly after.