In his title win Raquinel showed no fear of Nakayama, or of fighting in Tokyo. Instead he went about his business with the intention of scoring the biggest win of his career, stopping Nakayama in the 9th round of their bout, whilst up on all 3 cards. Other than his win over Nakayama there wasn't too much else on his record, a DQ win over Jimboy Haya, a split decision draw with Glenne Calacar and a majority decision win over Richard Rosales being the only things were even mentioning. Despite his thin record he has impressed, and he has risen to the challenges put in front of him and for such a youngster he looks like he has the ability to go a very long way.
As with many Filipino youngsters, though obviously not all with Mark Anthony Barriga being a notable exception, Rqauinel is a bit crude, a rough around the edges fighter who has heavy hands, a good engine and a second of toughness. He looks like he's a fighter who really could be moulded into an excellent fighter if he got the right training. There is a lot of natural gifts that he appears to have, and really just needs the right training to develop the skills to go with those gifts.
The challenger made his debut back in 2012 and reached the Flyweight Rookie of the Year final in 2014, losing a decision to the then unbeaten Kenya Yamashita. In 2015 he would suffer his second loss, being stopped by Tetsuya Hisada, who has since gone on the claim the Japanese Light Flyweight title. Since losing to Hisada we've seen Kosaka rebuild his career, going 6-1 (4) with a notable win against Yota Hori last time out, and a very close loss to Akinori Hoshino. Sadly the other wins were against most limited opponents, and it's hard to know how good he really is. A win over Hori is decent, but given that Hori had lost 3 of his previous 4, and was stopped last time out by Ryota Yamauchi, it's hard to put too much value on the win.
At 23 years old there is potential for Kosaka to become a really good fighter. He has got some skills and appears to be developing in terms of his power and physical strength. Sadly, though similarly to Raquinel, he really needs to be taken under the guidance of a top trainer if he's to reach his potential, which is likely to be below that of Raquinel. He doesn't seem to hard, have the speed or the experience to cope at title level, and has yet to go beyond 8 rounds. He might see this bout as a chance to prove himself, but it would take a career best performance to even test the challenger.
Given that Kosaka looks to lack in terms of power and top tier experience we are expecting to see him being stopped by the champion. Kosaka has got a chance of springing the upset, but needs to put everything together to defeat the impressive Filipino, and we'd be very surprised to see Kosaka see the final bell, never mind spring the upset win.