Is this the only proper movie about Hikiko-san? That was my first reaction, but no.
Hikiko: The Descent is also impressive... and the two films have the same director and writer. Anyway, this one's excellent. It feels like a proper movie, not straight-to-video nonsense. It's absorbing and, towards the end, genuinely scary.
Our heroes make a YouTube show called KaiKai Channel, supposedly investigating the truth behind scary stories. In fact, they're bullshit merchants. If they can't find any suitable interviewees, they'll get an actor to spout blatant garbage. The producer and the director are always arguing. Someone dies after they've broadcast a bullshit video about Hikiko, in which they got a (male) actor to dress up as a stringy-haired J-horror ghost... so they see this as an opportunity to make a sequel. (This upsets their presenter, Inami Chie.) Their dodgiest deed is to interview a disturbed, crippled boy who'd said "no filming" and secretly film him anyway, with a video camera hidden in Chie's bag.
"It's already rolling, so you don't need to do anything."
"Is this really okay?"
"If he notices, we'll just talk him round. Worst case, we'll hide his face with a digital mosaic."
This is like a mockumentary (and this film's writer and director also made a found footage J-horror series called Not Found)... but it's slightly different. Most of the footage we see is from a behind-the-scenes video, shot by a different cameraman. This makes the movie more like a conventional film, but still keeps a lot of the strengths of the mockumentary. The last act is scary. KaiKai Channel might have offended Hikiko-san herself with their disrespectful portrayals and they're about to learn what happens when you annoy a J-horror ghost. (Hint: draw up a will now.)
Hikiko herself works well, but adheres more closely than I'd have liked to the J-horror stereotype of the long-haired ghost girl. It's a strong image, though. I see why it's persisted. She gives her victims plenty of time to realise what's coming, but by the end of the film she's stepped up a gear. The film's not deep into Hikiko lore, but they know about the important one. She drags people. That's nastier than it sounds.
Also, this is a Hikiko-san film with no bullies. I'm grateful.
The cast are good, but personally I wouldn't have employed Chie as a presenter. It's the head-nodding. That's very Japanese, but you'd still expect someone to mention it. Overall, this is a strong, memorable J-horror that shines a cynical light on its chosen brand of YouTube nonsense and does surprisingly well at bringing traditional horror ghosts into the internet age. That might sound like an unnatural combination, but here it works. I'm a fan of this one.