A theme in fictional works where a character who sees themselves as "impure" (common examples in erotic works are non-virgins,
prostitutes, used goods, and damaged goods; common examples in non-erotic works are criminals, sinners, and people with zero sense of self-worth in general) is moved by the
compassion of another character, hence "purified". The
important part is that the impure character no longer feels impure, either temporarily or permanently.
Non-virgin: You shouldn't fall in love with me. I'm... not a virgin.
Chad: That doesn't matter to me.
I love you, no matter
what you are.
Reader: So this is purification...
not bad at all...