female humanoid shin Godzilla ww2 au fanfiction

after the atomic bombs fell on Japan something was affected by the radiation in the water and several months pass by and dead fish started appearing and strange sightings of something swimming in the water kept piling up then soon enough this thing came up and attacked and it's in it's fourth form as of now and it appears to be female but strangely almost human.. I am Aiko and I was only around 16 year's old when this "incident happened"
How many months have gone by since the shin's have been increasing in numbers..?
I know they are misunderstood. The military keeps trying to kill and destroy them.. eventually they will evolve further and created "monster's" but we are the true monster's..