2012 All Japan Indoor Tennis Championships – Singles

Dominik Meffert was the defending champion but decided not to participate. Tatsuma Ito won the title, defeating Malek Jaziri 6–7(5–7), 6–1, 6–2 in the final.

Seeds
• # 🇯🇵 Go Soeda (second round)

• # 🇹🇳 Malek Jaziri (final)

• # 🇯🇵 Tatsuma Ito (champion)

• # 🇯🇵 Yuichi Sugita (quarterfinals)

• # 🇹🇭 Danai Udomchoke (second round)

• # Yang Tsung-hua (second round)

• # 🇦🇺 Benjamin Mitchell (first round)

• # 🇫🇮 Harri Heliövaara (second round)