Bean Sprout Ramen （もやしあんかけラーメン）

There is a cafeteria right next to class room building in my college,
and I always sneaked out around 3pm to have this Ramen there.
Since bean sprout is very cheap  even in Japan, somewhere around 30 cents per bag, this Ramen was also very cheap ~ $3. I should check if they still have this menu !
Oba-chan who makes this Ramen suggested me to put a little bit of vinegar, and this became unforgettable taste for me. Bean Sprout sauce is creamy and sweet, and vinegar brings up the sweetness in nice way.