Antti Litja, who had already provided voice for the Mielensäpahoittaja character in the original radio plays and played the role in theatre, was initially not enthusiastic to appear also in the film, but eventually agreed after his grandson encouraged him to take the part.
The S-Card that Mielensäpahoittaja needs to get into the toilet is a Customer Loyalty Card.
Mielensäpahoittaja mentions hearing Nevala win at the Tokyo Olympics. Pauli Lauri Nevala was a Finnish javelin thrower, who unexpectedly won gold at Tokyo in 1964.
Neither the son nor the daughter-in-law are named in the credits, just credited by their relationship to the Grump. The son does refer to his wife as Liisa (and Lissu, a term of endearment) in the English subtitles.
Arvi Lind was a Finnish television news presenter, working as the news anchor on Yleisradio TV1 from 1965 to 2003. Matti Rönkä (1959 -) works as a news anchor for the YLE TV. He is also an author of eight crime novels.