It may be at his lungs by now
Sorry, science geek here to ruin things ლ(´ڡ`ლ). The heart is already placed between the lungs, and there are actually multiple cavities in our body made from thin membranes that hold our organs in place, not only that, but the super thick veins and arteries that run into the heart would burst from the pressure if his heart was moved to any place other than where it belongs and he would die of internal bleeding. Really the only organs you could move without major consequences is the small intestines, also known as the "guts". Hence the phrase "rearranging his/her guts"
Lol
Would you please write a thriller BL? With this knowledge, it'd be fascinating (╯°Д °)╯╧╧
Dead ╥﹏╥
At this point, Kouchi heart beats next to his kidneys (●￣(ｴ)￣●)