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.