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. Muramatsu entered PDC Qualifying School and was knocked out in the last 16 on two of four days which helped him finish inside the top 18 on the Order of Merit who earn two-year PDC tour cards. 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.