The WBC Youth Titles, which are often seen as a stepping stone belt for young fighters on their way up, is an often over-looked belt due to the fact fighters fight for the belt before they are well known. Despite this they have been held by some very notable fighters including international stars such as Humberto Soto, Jorge Arce, Chad Dawson, Timothy Bradley, Saul Alvarez and Leo Santa Cruz.
As well as the international fighters the titles have also been a major stepping stone for some notable Asians including Oleydong Sithsamerchai, Pungluang Sor Singyu, Wanheng Menayothin, Yodmongkol Vor Saengthep and Tomoki Kameda.
In regards to the two fighters Matsumoto is probably the slightly better known. The 23 year old Japanese fighter has been a professional a little over 5 years and although his record is marked up he has faced some decent fighters such as Yu Kawaguchi, who fights for the Japanese national title later this year, and Jaesung Lee a 2-time Korean national champion.
Although lesser well known Kim does have "the better record" and is currently on an 8 fight unbeaten run. Saying that however he has been fighting limited opponents which could explain his impressive looking record. Notable though those victories will have filled him with confidence and he may well believe that he's the better fighting going in to the excellent "lower level" match up.
(Picture courtesy of http://www.boxing.co.jp)