[3] Saito entered the apprentice school that same month at the rank of 6-kyū under the tutelage of shogi professional Masataka Sugimoto.
[6] After being promoted to 2-dan, Saitō's progress stalled and poor results led to his demotion back to 1-dan, which he said was quite discouraging because he found himself competing against elementary school and junior high school students even though he had already entered university by that time.
[2][6] Saito began the 71st 3-dan League (April 2022 – September 2022) seeded 39th out of 41 players, which meant he would be at a disadvantage when it came to tie breakers.
[6][7] His 3-dan league opponents, however, were closer to his age which made him feel less pressure to win, and he entered the final two rounds of play tied for first.
[6] After splitting his final two games and seeing some of his closest competitors falter, Saitō obtained full professional status and the corresponding rank of 4-dan in September 2022 by tying for first with Nagisa Fujimoto with a record of 13 wins and 5 losses.