Under the "Visas" section of the foreign affairs website it is described as:

"Short-term stays refer to temporary visits of up to 90 days for such purposes as sightseeing; sports; convalescence; visits to relatives, friends, or acquaintances; amateur participation in athletic meetings or other contests; business trips (such as market surveys, business liaison, business talks, signing contracts, and after-sale service for machinery imported into Japan); and friendship visits. These activities require either a temporary visa or transit visa. (However, this category excludes profit-making operations and paid activities.)"

Just a yellow stamp in the passport labeled:
"Landing Permission"
"Status: Temporary Visitor"
"90 days"