A small bar in Tokyo's Nakano Ward is becoming popular with middle-aged men who like to make plastic models of characters from the "Mobile Suit Gundam" cartoon.

"It's like a secret base," said Kentaro Nonaka, 36, a company worker who lives in adjacent Suginami Ward and drinks there once or twice a week.

The bar, Professor TK, is filled with boxes of plastic Gundam models. It all got started with four men in their 30s and 40s sitting at the counter talking about the smash-hit animation series from the 1970s and 1980s. They all met at the bar and became regulars.

"Other customers can give me tips on how to make the models," said Nonaka one night as he pulled out a model and started painting its small parts in black. "I can share my hobby with them."

The owner, avid Gundam fan Takeshi Koyama, 48, opened the bar in December 2014. He said there are times when customers simply work quietly on their models rather than chat with others.

"Casual drinks at a place where they can share their hobby will allow them to enjoy them both in a comfortable manner," said Takuya Kano of the Sakebunka Institute, which offers research on liquor and its culture.