@Nike
Uhmm, did you read this manhwa properly? They literally showed that before they escaped Union Busan, Narisa Na wasn't even pregnant yet, and they showed they showed once more that she was pregnant only when they were on the boat that they've escaped from... Bota wasn't literally even born yet when they escaped at that time and Kana's already 14 years old, heck she might even be 15 years old since we don't know how long she has been as a harpoonist applicant that time... how in the world did you get the 3 years age gap?
Anyways, they shouldn't be in a relationship as it's just very weird, your guardian who's 14-15 years older than you and helped raised you and would want a relationship between these two, please no...