Act 1 Donkey Kong
We have Donkey Kong senior/cranky Kong finds a warp pipe to Brooklyn/ New York/New Donk City chasing an unknown figure

Mario is a construction worker on the site helping build the house and installing the plumbing while this happens and during the chaos the house is destroyed that was due to Cranky Kong chasing the unknown figure

Incidentally during the chaos of the chase mayor Pauline was in danger with building collapsing and Donkey Kong rescue Mayor Pauline who was mario girlfriend however she screams with the danger and Mario interprets this is a kidnapping

mario battles Donkey Kong and rescue Pauline and Mario is the hero of the city

Act 2 Donkey Kong Junior
mario captures Donkey Kong/Cranky Kong and guards him in prison. cranky is insistent he is innocent and Mario doesn’t believe him as he saw him destroy the building while chasing an unknown person.

during this Donkey Kong Junior/Donkey Kong tries to rescue Donkey Kong/Cranky Kong. Mayor Pauline starts to believe Cranky Kong and tries to convince Mario but he is too stubborn and during this time New York/New Donk City is being destroyed and Mario assumes this is Donkey Kong Junior is responsible

Donkey Kong Junior tries to rescue his father and defeat Mario but surprisingly when Mario is about to fall to his death, Donkey Kong and Cranky Kong Rescue Mario.

mario is surprised and realised that he kidnap an innocent person and tried to stop a son trying to reunite with father

ACt III Donkey Kong Bananza
it was revealed that the real person causing destruction to New York was King K Rool and that he was the mysterious figure that Donkey Kong/Cranky kong was chasing at the beginning (similar to the twist ending of Bananza)

Mario, cranky Kong, Donkey Kong Jr while carrying Mayor Pauline on his back team up to stop King K Rool and they win

Mario apologise to the two monkeys. Pauline breaks up with Mario due to him not listening to her

post scene credit
Mario decides to leave the construction industry and becomes a plumber working with Luigi but thens discover a warp pipe to the mushroom kingdom amd he finds a Toad who asked them to help to rescue Princess Peach