Without specific knowledge of "Ingoku no Houkago 2," one can only speculate on its plot:
The second installment delves deeper into [major plot points or character arcs].
"Ingoku no Houkago" or its sequel, presumably titled "Ingoku no Houkago 2," seems to refer to a work (possibly a manga, anime, or light novel series) that might explore themes of high school life, post-graduation experiences, or perhaps more fantastical or psychological elements hinted at by the term "Hell's" in the title.
