This post was a reader’s request. Here’s to you, Megatron. I’ve been involved with sports in public school and in the community. I’ll generalize what I’ve seen.
The most popular sports are baseball and soccer. Baseball is often shown on TV, but I don’t know anyone who watches regular season games. Most people just watch the highlights or read them in the newspaper. However, a lot of people get into baseball during the playoffs. A lot of folks cheer for the local team at sports bars and pubs. People suddenly seem friendly and more open towards each other.
Soccer is more popular to play than it is to watch, especially with younger students. I haven’t heard of any girls who play though. It’s mostly middle and high school boys. A deviation of soccer, futsal, is more common with men in their twenties. There are lots of futsal clubs for working age people.
Sumo is popular for the older generations to watch on TV. I’ve never met anyone under 45 who was interested in sumo, but it happens to be the national sport. It is pretty exciting to watch, and I would love to see a real bout. I hear it’s a great experience.
Football (American) and hockey are non-existent. People know what they are, but I haven’t met anyone who knows the rules or who has watched a game. The biggest presence football has in Japan is with the manga Eyeshield 21 (I have no idea how well it’s represented). I’ve heard that there are private company football teams, but they certainly are private, or hidden, because no one knows about them. Some high schools and many universities have a rugby team. This is not football though. Most people I’ve met seem to think rugby and football are the same.
Basketball is somewhat popular (thanks to Slam Dunk and Buzzer Beat). Sadly this hype usually finishes in high school level. The professional league (JBL) is far behind the NBA. It doesn’t even come close to the NCAA. I’ve noticed a lot of people (especially girls) shoot with both hands (like a chest pass), and a lot of players jump when shooting free throws, which is never seen in the USA or Canada. (FYI, you are allowed to jump on free throws.)
Another interesting comparison: In Canada I lived mostly in Halifax, Nova Scotia, population of 375,000. Within city limits there were many outdoor basketball courts. I can easily count over ten off the top of my head. Nagoya has a population of 2.2 million, but I’ve only seen 1 outdoor basketball court and it’s a half court! It gets packed on weekends and holidays with Chinese, Filipinos, and Americans. Very rarely can you see Japanese there.
Volleyball is common with both boys and girls. Tennis is more popular with girls. Ping pong is not uncommon; some schools have teams. Most middle and I think all high schools have a pool to teach swimming in PE. Most schools will also have a swimming club.
Golf is popular with a wide demographic. There are driving ranges all over the place, and some are open 24/7. You can see a lot of ojisan and salarymen practicing their golf swing with umbrellas while waiting for the train.
Ironically, martial arts is more common in the West. In Japan Judo is the most popular, followed by Karate. Kendo clubs attract members at the high school and university level, but I don’t know any Japanese of working age who practices martial arts. I know a lot of people in Canada who do. Just in my family there are several black belts in Tae Kwon Do and Judo. I have a brown belt in Karate.