Ekiden is a popular long-distance cross-country relay footrace competition in Japan. There's no fixed format; a race may have teams from 5 to 10 people, and the running distance per runner may vary from a kilometer to a half marathon. Most races are school-related events, with teams from different high schools or universities1.
Some large ekiden events are highly competitive, very serious and even broadcast on TV. Others are less so, and the departmental ekiden held at NAIST each autumn is decidedly in the latter category. Some teams take the race somewhat seriously and train beforehand. Other teams simply take it as an excuse to dress up, get out of the lab and have fun in the autumn sunshine for an afternoon.
Mathematical Informatics teams, with a Hayao Miyazaki theme. And yes, 'Miyazaki' to the left ran the course holding that bug thing over his head. Our other team did take it seriously, and won the race.
#1 Japan has a system where you do sports and other non-academic activities at your university, not in separate clubs or associations. Seems a little restrictive — what if you want to join a friend at a different school? — but who am I to judge; as a student I never did any sports at all.