In comparison with English verse typically characterized by syllabic meter, Japanese verse counts sound units known as "on" or morae. Traditional haiku is usually fixed verse that consists of 17 "on", in three phrases of five, seven, and five "on", respectively. Among modern poems, "teikei" ( fixed form) haiku continue to use the 5-7-5 pattern while "jiyuritsu" ( free form) haiku do not. However, one of the examples below illustrates that traditional haiku masters were not always constrained by the 5-7-5 pattern either. The "jiyuritsu" was advocated for by Ogiwara Seisensui and his disciples.