Mantis Shrimp's Calculation (シャコの計算 Shako no Keisan?) is the one hundred and ninth chapter of the Dandadan manga series.
Summary[]
Mr. Mantis Shrimp struggles against the mantis suit alien, who acknowledges him as being a tough opponent that helps him to enjoy the suit's full functionality. Mr. Mantis Shrimp flashbacks to him tucking Chiquitita into bed as he is about to head out to meet up with Momo and the others for the upcoming battle. He then runs into the woman he works for who worries for his well-being after he started to come back home with bruises and eases her mind by telling her that he will come back to continue raising his son. Mr. Mantis Shrimp wishes to go back home and runs into the river, causing the mantis suit alien to interpret his action as an act of cowardness. However, Mr. Mantis Shrimp clarifies that he will fight him on his own turf and will continue to repay his debt to the people who helped him. The mantis suit alien then has his suit switch to its water form and states that he is 100 times stronger when fighting in the water, which proves to be true as Mr. Mantis Shrimp becomes too overwhelmed by his attacks to fight back and is pierced with a needle that injects him with venom. Mr. Mantis Shrimp tells the mantis suit alien that he is hard to fight against due to his large size but can now hit him as long he is close. Mr. Mantis Shrimp damages the mantis shrimp alien and states, as he transforms, that he is now twenty-four times stronger with punching power that is increased to being ten times greater under water, making him 240 times stronger in total. The mantis suit alien refuses to believe him but ends up being struck by Mr. Mantis Shrimp's Jet Punch that destroys his suit, causing the latter to comment that it was an incredible clean hit. He then swims to the surface to catch his breath, returns to his normal form due to only being able to last for twenty-four seconds, and releases the venom from his body, stating that he is immune to it due to his race being fighters despite him being categorize as weak. As he walks off, the mantis suit alien explodes from the water.