I have played this game for many times and has actually trained characters to level 99 (highest possible level) occasionally. Usually every 10 levels has a rank; here are the Japanese names for the ranks and their rough translations:

About Level 1-3: 見習 (trainee)
About Level 5-19: 劍客 (Swordsman (low level))
Level 20-29: 劍士 (Swordsman (mid level))

The above 3 Japanese terms are definitely there but I forgot exactly which levels do they start at and which levels they end at. Maybe there is a 4th rank... I can't remember. But for the below ones I am very sure.

Level 30-39: 無雙 (Peerless)
Level 40-49: 名人 (The Famed)
Level 50-59: 達人 (Expert)
Level 60-69: 劍豪 (Honered Samurai or Swordsman at high level)
Level 70-79: 劍聖 (Sword Saint)
Level 80-89: 劍鬼 (Sword Demon)
Level 90-98: 劍神 (Sword God)
Level 99: 天舞 (Pronounced as Ten-Mai, I don't know what it means but it is something like a heavenly god)