Students commonly refer to their school as Todai (Tokyo Daigaku). It's 30,000 students are amongst Japan's brightest. About 2,000 of them are international students.
Officially Keio University is Japan's oldest (1858). However, Tokyo University has it's roots in Edo-era academic institutions such as the Astronomy Agency (1684) and the Western Books Translation Agency (1811). In many ways, Todai is Japan's oldest academic institution.
Todai pumps out massive amounts of cutting edge, world class research every year. It has an equal number of graduate and undergraduate students (roughly). Seven of it's alumni are Nobel Laureates.
Despite its academic reputation Tokyo University also has a strong sports lineup. Its 46 varsity teams often rank nationally.
Todai entrance exams are amongst the toughest in the Japan. Exam day has a festive atmosphere.