Another mini trip that can be good to do in a group can be going somewhere educational. Namely a museum. Lots of them are around and finding something you both enjoy can make for a nice afternoon outing.
In my town they offer a train museum. Seeing the history of the various trains and seeing them on exhibit was really neat.
So if you like educational outings keep it in mind.
If you are a foreigner looking for Japanese women or Japanese singles, then please try out EXEO International’s speed dating events. Events are offered on Fridays and some Saturdays.