Papamochini Ekadashi is observed during the waning phase of moon in the month of March/April. The story or Katha associated with Papmochini Ekadasi was narrated to Yudhisthira by Lord Krishna. The story narrates how one can get rid of sins by observing the Papamochini Ekadasi Vrat.
Once sage Medhavi, an ardent devotee of Lord Shiva, performing Tapas (austerity) a forest named Chaitraratha. The forest was famous for its beautiful flowers and was frequented by Indira, demigods, apsaras and other heavenly beings.
Apsaras, or damsels of heaven, tried to disturb the meditation of the sage but was not successful.
An apsara named, Manju Ghosa betted with other apsaras that she will captivate the sage and disturb his tapas. For this she built a small hut not far away from the spot where the Sage was meditating. She used to sing songs and play Veena.
The sage soon went in search of the source of the song and discovered the beautiful Manju Ghosa. On seeing, the arrival of the sage, Manju Ghosa applied sandalwood paste and wore beautiful flowers. The sage was captivated by the surrounding and was overwhelmed by the beauty of Manju Gohsa.
The sage lost his sense and became a slave of the beauty of the apsara. He forgot his devotional service and stopped discriminating between day and night.
Manju Ghosa thus won the bet and was able to disturb the sage. She soon lost interest in the sage and decided to leave. The sage then regained his senses and realized that the apsara had tricked him and broken his tapas. An angry Sage cursed Manju Ghosa cursed that she will become a witch.
A depressed and fallen Sage Medhavi returned to his father Sage Chyavana and told him about his fallen state. Sage Chyavana asked his repenting son to observe Papamochani Ekadasi which will help in removing the sins.
The Sage observed the Ekadasi Vrat and was able to get rid of the sins.