While Catholics are currently only a small percentage of the total population in Japan, there is a good number of vibrant Catholic communities in Japan. I love to attend masses in Japan for many reasons. On the one hand, I could admire the universality of the Church and notice all of the similarities in the liturgy. On a more practical matter, I could practice my listening skill by listening to the responses and the homily, and practice my reading skill by reading the responses.
While I loved all the churches I visited, the church that I went to the most often was St. Ignatius Catholic Church in Yotsuya. This church is attached to Sophia University, and is a large Catholic hub for many communities. They offered masses in English and Japanese masses every Sunday, and Vietnamese, Portuguese, and other languages on some Sundays. Conveniently placed next to the Yotsuya train station, many people gathered here on Sunday for mass, Bible study, and other activities.
The other churches that I was able to visit was Meguro Catholic Church, the Franciscan Chapel Center, and the Kichijoji Catholic Church. The Kichijoji Church is the nearest church to where I lived, being two train stations away, and is a local church.
It was interesting to see some cultural differences during the masses, such as no genuflection, but overall, it was inspiring to see the Catholic faith in a different environment.