From the build-up and the actual setting plus plot goal, yes, we can safely assume that the story will get a lot of harem elements as well as much more sex considering only Yukine's content alone and the steamy situation with MC and his sister in the last chapter. There is a lot of build-up that is for sure and we still have girls/women that have had no build-up or sexual content at all, not counting the 2 unknown ones we have yet to learn about or confirm are going to be part of the harem. Dev said themselves 8 girls all in all will be part of the MCs harem.
*Loaning the list that
d_pedestrian made:
1) Hikari (Infatuated Sister)
2) Akemi (Tenderly in love adoptive mother/best friend of biological mother)
3) Sayumi (Wife from future/we have yet to meet her contemporary self - and the one enabling/creating his harem)
4) Yukine (The long desired and on-hold childhood love of MC - it's reciprocated)
5) Hime (The high school classmate that crushed heavily on MC and that MC left heartbroken due to his love and loyalty for Yukine)
6) Kanehana (The heavily enamored newcomer and rising idol star that the MC becomes manager of per her own wish)
7) Unknown
8) Unknown
A guess for the two unknowns so far are MC's mother Rin transported from the past (prior to her passing/now probably cured) and MC's and Sayumi's yet to be born daughter from the future that goes by the name of Rysa (Probably a play on the name Risa). But this is as of yet pure conjecture and has not been denied or confirmed. Rin (MC's mother) has a strong potential of being part of the harem due to how much of a part she played in the life of MC and Akemi, and the really vague info about her "passing" as well as the unknown dad. Since one of the themes is time travel, the possibilities are rather many.
With all of these women and how much content Yukine alone has, I'm wagering that the amount of sexual content is going to be rather large. At this very moment, the game is in the character introduction stage, so I'm expecting it to be well over 15+ chapters at least.
