The plot revolves around Sourav (Taabbu), a clerk who falls in love with a girl staying beside his building. Later he finds out that the girl, Joita (Rittika), whom he loves, is about to get married to a person named Konar (Rajatava). Here comes the twist as Sourav used to think that this man was her Father. He finds out that she has no other way but to marry him who is more than double of her age. Sourav offers help to save her and she agrees, but his plan fails and both get caught. Now, the real story begins which leads to a tragic end.This is a story about an underdog and his life mingled with a girl bound in chains of torment. 'Kothay Tumi' sheds light on the dark side of society and its ruthless system.