There is some sense there. Old Xian is fantastic at signposting early and subtly.
*Pushes glasses up* *Deeply inhales*..... if you look at ch 45 (on the mangadex listing) it says that Jian Yi was kidnapped on the second day of high school. We still have a bit to go on that one. They have to finish the academic year and have summer break etc. The next chapter implies that his father's suited henchmen took him to an island. We kinda know that his father is involved in some kind of violence (ch 105) and his mother has left him for it. JY's Mom is absent a lot (ch. 235), what is she doing? JY doesn't seem to know. Despite her distance from JY's father, when she disappears in Ch235, Brother Qiu shows up with money! I agree there is something brewing that the kids have no idea about, ch 241 describes the situation as "tense". I just love how Jian Yi is so indifferent to being kidnapped a lot (3 times is my count, once by the guy who wants revenge on his father, twice by He Cheng/Brother Qiu), and having weird stuff going on. He is a spectacular airhead, that doesn't dwell on stuff much. He doesn't seem to be affected by all this negative stuff like He Tian, She Li or little Mo.
She Li, threatened to get revenge on JY when JY smashed a bottle of orange juice on him (ch 203). We know SL is the kind to hold a grudge. SL also has beef with He Tian for the whole blackmail incident and the symbolic fight (He Tian sustains a neck cut protecting the one he loves, just like his brother He Cheng). She Li was in the story from ch 117 (we only see his bracelet and rings....serious props for story planning there! but he was part of the long term plot from early on). He doesn't show up until ch 177. We know his family has bars (ch178), money and resources . Ch 293/294 we get the first bit of development. He observes He Tian and little Mo being close and he seems displeased. We see a flash into his troubled youth, and a sense of sadistic possessiveness over little Mo.
The big questions is what/which gang destroyed Little Mo's family restaurant, which resulted in a murder conviction for his Dad and general financial ruin?
Where is Jian Yi's mom? In 279 she tells JY to go with Brother Qiu but then isn't heard of again.
He Tian's brother (He Cheng) works for Jian Yi's father. Ch 168/192. He Tian's father owns an island?. There is a new partner/wife, He Tian doesn't get along with her. (251), in that chapter He Tian's father says that to leave the island would depend on his "abilities". This could be part of the reason why it took JY so long to come back. But It seems that EVERYONE has an island, even He Cheng (302) so that makes it difficult to pin down, who and where.
He Tian is staying in his "uncle's empty house " Ch 144. It is likely that could be Mr. Jian. Although "uncle" is a general term to address an older unrelated male. I am going to go with my gut and say Mr Jian. It is possible that Jian Yi and He Tian are cousins but at this point Old Xian is dropping vague hints to drive us crazy on purpose. He Tian knows a lot about Jian Yi's situation, possibly more than JY, as we see during the kidnapping arc when he advises Zhan Zheng Xi.
I think a lot of maneuvering is happening to get characters ready or in place for a total cluster fudge action arc. A lot of little things are happening to build up tension (as mentioned above) but Old Xian is the master of leaving small details and not making a huge deal about them, but allowing them to be come key features whole story lines hinge on 50 chapters later. First though, I think we will have some deep emotional, hidden past stuff and significant bonding to occur first. Tragedy only gets bitter sweet when there is more to lose.
Thank you for attending my Ted talk.