Every day around 5.30am Khid-da would be at Rabindra Sarobar watching how young swimmers were being trained.

Veteran coach Anil Dasgupta would stand on the banks and rotate his hands vigorously in the air to teach learners how to negotiate the waters and surge ahead. Khid-da would watch Dasgupta intently.

Soumitra Chatterjee —Khid-da in Koni — started his morning rounds around the south Calcutta water body soon after he was approached to play the role of a swimming coach in the film.

“We were amazed and awestruck by his dedication,” recounted Sriparna Banerjee, who played the title role in the 1984 film. Sriparna is now the teacher-in-charge of the nursery section of South Point School.

Koni went on to win a national film award and Khid-da’s motivational chant — “Fight, Koni, fight” — became sort of a war cry for generations.

A still from Koni Sourced by The Telegraph

Soumitra had said on several occasions how he would chant this phrase to lift his “ageing spirit”.

Directed by Saroj Dey, Koni revolves around the story of a coach and his trainee, Koni, who fights all odds to make it to the victory stand. Khid-da, who teaches swimming to underprivileged kids, picks Koni from a slum and grooms her to be part of the state team to compete at the national championship.

Sriparna recalled a scene at a swimming pool in Hedua, where Koni tries to run away from practice and Khid-da wants her to carry on for some more time. “Soumitra-babu ran down and jumped over a row of railings sporting a dhoti and threw a stick to stop Koni from leaving the waters. The entire unit was amazed at his level of fitness,” said Sriprana, by then a national record holder for swimming.

The bonding between Koni and her Khid-da started with Soumitra turning up at Sriparna’s house for the screen test of the film. “Soumitra-babu drove down in his white Ambassador from Lake Temple Road to my house on Hindustan Road. It was my first introduction to him and I still can't get over that someone like him would drive down to my house,” Sriparna said.

“I then practised at Indian Life Saving Society. We sat down for his interpretation of the storyline and the role of Khid-da.”

Over the next few years, the film unit would travel to several locations in Calcutta and to Chennai and the bonding between the coach and the disciple would grow stronger. "At times when we would travel by car from one location to another and get caught in a traffic signal, he would suddenly start singing aloud or recite poems," reminisced Sriparna, who represented Bengal in several inter-state swimming competitions.

“Over the years every time we would meet, Soumitra-babu would break into a warm smile. ‘Ki rey kemon aachsih (Hey how are you?),’ he would ask. He would enquire about my family,” Sriparna said.