This is absolutely amazing. I was directed here by a school friend who told me that this was a really famous taiyaki place in Yotsuya. It has an excellent reputation among Japanese, apparently, and deservedly so. It was piping hot and the red bean paste was delicious. If you're looking for a good place to eat taiyaki, definitely go out of your way to go here.
The name of this place, Taiyaki, is I believe it's only product. Taiyaki is waffle batter placed into the mold of a fish and filled with a sweet red bean paste. The Taiyaki is made fresh to order, and is obviously popular with the locals as there was a very long line. Personally, I do not find taiyaki all that delicious and exciting to eat. it was a bit too sweet for my taste. However, one of my friends who is a big taiyaki fan said it was amazing. Either way its worth checking it out as each fish is only 140 yen. To find it cross the street after exiting the JR Yotsuya station exit and walk right. When you see a small mochi shop turn left. You can't miss the line