Note: In Japanese it is common for there to be multiple readings for even a single 漢字 (Kanji; Chinese originated) character. Among the multiple readings for 優 include both ゆう (Yū) and まさる (Masaru). According to NDL-Authorities and Wikipedia-JP, his offical given name is read as まさる (Masaru; and has used the initials "M. M." for "Mori Masaru") but many native Japanese speakers confusingly read it as ゆう (Yū; due to its common use as a female given name) at least initially. Well know via the pseudonym 南山宏 (Minamiyama Hiroshi) named after his elementary school, he is also known to have used the following other pseudonyms: 大山優 (Masaru or Yū Oyama) and 森勇軒 or 森勇謙 (both read as Yuken Mori)