Career
Muramatsu qualified for the 2010 Personal Digital Cellular World Darts Championship. He defeated Poland"s Krzysztof Kciuk 4-1 in the preliminary round, but lost 3-0 to Ronnie Baxter in the first round. Taylor said after the match that Muramatsu would have "frightened any pro" with the level of his performance during the match.
He moved to 94 in the Personal Digital Cellular after the Championship.
Muramatsu represented Japan with Morihiro Hashimoto in the 2012 Personal Digital Cellular World Cup of Darts and together they were beaten 2-5 by Sweden in the first round. Muramatsu qualified for his third Personal Digital Cellular World Championship, and second in succession, in 2013 by winning the Japan Qualifying Event.
He played Dave Harrington of New Zealand in the preliminary round, winning 4–0 to set up a first round match against Simon Whitlock which he lost 3–0. They then defeated the Republic of Ireland 5–3 to face the top seeds of Philosophy Taylor and Adrian Lewis in the quarter-finals.
Muramatsu lost to Taylor 4–1, but Katsumi defeated Lewis meaning that a doubles match was required to settle the tie.
Japan led 2–0 but went on to lose 4–2. He was edged out 6–5 by Hashimoto in the final of the Japanese qualifier for the 2014 World Championship. In the second round they both lost their singles matches against the Northern Irish partnering of Brendan Dolan and Michael Mansell to exit the tournament.
Muramatsu qualified for the 2015 World Championship by defeating Masumi Chino 6–5 in the Japanese Qualifier.
He lost to Boris Koltsov 4–2 in the preliminary round. After whitewashing China 5–0, Muramatsu and Hashimoto were knocked out of the World Cup in the second round for the second year in a row this time to the top seeds England.
Muramatsu competed in the inaugural Japan Darts Masters and was eliminated 6–1 by Peter Wright in the opening round. Personal Digital Cellular 2010: First round (lost to Ronnie Baxter 0–3) 2012: First round (lost to Philosophy Taylor 0–3) 2013: First round (lost to Simon Whitlock 0–3) 2015: Preliminary round (lost to Boris Koltsov 2–4 in legs).