Year end ceremony happens in the intro, after that Hailey drags Hifumi away, and informs him that for the spring break, they're going to Korea. It's finally time to formally introduce him to her family.
Family drama dinner. At night there is an attempt at Hailey's father's life. He survives (but the butler might be dead). The mansion goes on auto lockdown, so it ends up with a classical "the killer is among us" situation (they want to deal with it internally first to avoid a PR scandal or due to care for their relatives, depends on the person in question). Accusations of who wanted to get rid of him, whether it was some sort of a grudge, or an attempt ar taking over the chairman position and so on.
I'm still in the process of outlining the whole intrigue. Coming with possible motives for everyone (and not mixing them up), setting a couple plot twists (and not making them obvious, but also making them make sense), and patching any holes in logic I find (each time I deal with one, two others pop up).