There is a way to enable B-shutter on your gakkenflex! All you need is a piece of rubber band and some little techniques!

Step one -
Hold down the shutter level, but don’t go all the way down, pull it 82% down, there will be a really light “click” to it.

Step two-
Release slightly until your shutter lever is stuck at 50%.

Tada! You can now get a tripod and start the long exposure shots!

What? I don’t wanna leave my hand there for the next 30 minutes while I shoot star trails!! Alright, alright, calm down. I have an idea, and that is using a rubber band. To learn how, Please look at the video above.