2013 All Japan Indoor Tennis Championships – Singles

Tatsuma Ito was the defending champion but decided to participate at the 2013 BNP Paribas Open instead.
In the final, fourth seeded John Millman outlasted second seeded Marco Chiudinelli in 2 hours and 26 minutes to claim the title with a scoreline of 4–6, 6–4, 7–6^(7–2).