Oi tournament had status of title one in 1960. Professional players and two women professionals take part in this shogi event. 8 players by results of preliminary stage divided in to Red and White groups of Oi League. Time limit on this stages of Oi is 4 hours for player.
It is necessary to win 4 title games to get Oi title. Every title game plays during two days. Time limit is 8 hours for every players.
By materials of japanese resources
Andrei Kasperovich, 2006