A jonokuchi bout.
Jonokuchi (序ノ口 or 序の口) is the lowest sumo division. All wrestlers, apart from those who have had successful amateur careers and are given special dispensation to enter makushita or sandanme directly, start in this division. In addition to the new wrestlers the division tends to consist of other recent recruits to sumo wrestling as well as some older wrestlers who have fallen to the bottom of the ranks due to prolonged injury.
A new wrestler's initial position in the jonokuchi division is determined by his performance in maezumo, a tournament held among new wrestlers at the time of the grand tournament before they are ranked for the first time. The jonokuchi division varies in size and typically includes between 40 and 90 wrestlers, with the high mark being reached for each May tournament as the number of recruits appearing in maezumo is generally largest during the preceding March tournament, when the Japanese school year ends. As with the other lower divisions, wrestlers only compete in seven bouts over the course of the tournament. Jonokuchi is the only division in which wrestlers are semi-regularly promoted even with a losing record; promotions to the next highest jonidan division with a losing record are especially common for the May tournament when there is the large influx of new recruits.
The word jonokuchi is also used as an expression to describe when something has just begun.