Rubuta ci gaba don wannan sakin layi - A watan Oktoba na 1964, lokacin da Yokoyama ya kasance dalibi a Jami'ar Rikkyo, an zaɓe shi ƙungiyar 'yan wasa ta Japan don wasannin Olympics na 1964 a Tokyo. A wannan gasa, ya fara wasa kuma ya buga dukkan wasannin a madadin Tsukasa Hosaka ya karya hannunsa kafin wasannin Olympics. Bayan haka, Yokoyama ya zama mai tsaron gida na yau da kullun a ƙungiyar ƙwallon ƙafa ta Japan. A cikin 1968, an zaɓe shi Japan don wasannin Olympics na bazara na 1968 a Mexico City. Ya buga dukkan wasannin kuma Japan ta lashe lambar tagulla. A cikin 2018, an zaɓi wannan ƙungiyar a cikin gidan wasan ƙwallon ƙafa na Japan. Ya kuma taka leda a wasannin Asiya na 1966, 1970 da 1974.
Ka yi haƙuri. Ya buga wasanni 49 don Japan har zuwa 1974.