i am aware of what they can put in this manga, and thats what makes it normal and not some children rated cartoon from usaY woulld they not have teen preganices? Doesn't the real world have that. This is not a G rated anime/manga they curse they have people who seem like child molsters, pervs, drunkards, killers etc...
So them not having teen pregancy aleast 18 or 19 is not beyong this manga. Plus certain contries people get married when they are children. You assume this was just made for United States or some country where grown man on VHI shows who are like 35 who are having their first baby. Nope people can have it whenever.
3rd datebook show me in the manga where it says she is 54 or anime.
but nevertheless i dont think kishi would put in a 13-18 yr old mother which put her baby for adoption