After the Rocky III reference in an earlier chapter, we get a named reference to G.I. Jane. But Stallone also did one-arm pushups in Rocky IV. Not sure if Yugi ever did pushups in Yu-Gi-Oh.
Fun fact: there is actually such a thing as "broken heart syndrome," or takotsubo cardiomyopathy, named by a Japanese doctor after the octopus traps he thought patients' hearts resembled. Now, isn't that more than you wanted to learn from a middling high-school romance/assassin manga?