The inside also looked strange (kind of looked like a whole bunch of lychees). I had a bite, and to my surprise it was just so yummy!
At that time, we didn't know what it was, so I took a picture and posted on FB asking my Indian friends what it was. Immediately I got an answer saying it was "the" mangosteen!! I knew the fruit by name, but I never spent time to do a search to actually check what it looks like. I would certainly never have imagined that "the" mangosteen looked like that. Also I would never have imagined that I could actually eat it, as in Japan mangosteens are so expensive and rare. One mangosteen can cost up to 500 yen a piece (a little over $6). Here in India, my hubby doesn't remember, but I am sure they are much cheaper.
Although I was a bit afraid of trying different kinds of fruit after the incident with lovely custard apples, I think I have become a big fan of mangosteen! Mangosteen is also called "the queen of fruit", and it indeed looks like a pretty queen protected carefully in a thick rind, which is very very bitter btw (yep, I tried).