I had a friend visited Japan back in 2019 I believe (just before wuflu I know that much), they found a notable amount of people who at least alleged to practicing some form of Christianity (usually I was told they were either a catholic or a protestant) and tried to get people to convert and all that sort of noise. They even had to deal with some crazy Jehovah's Witnesses following them around to talk about whatever the heck they want like crazy stalkers. So take that however you want. From what I was told, the more you leave the major cities and you get into the country side the more likely you'll find Japanese practicing some sect of Christianity.
One of the biggest cult classic jrpg series, the Trails series, has the literal catholic church renamed, and one of the main party members one of that series' arcs is named "Father Kevin" who is effectively a catholic father with a typical jrpg twist.
Japan also likes to use Gnosticism ideas, another sect of Christianity, because it frankly makes a very good segway into a final boss where you fight God. One of the most popular recent examples of this is Persona 5 where you fight a boss named after one of the most common names for the Demiurge who is iirc meant to be the old testament God in Gnosticism.
I don't think Japan hates western religion persay, at least enough for it to a massive problem as Japan is xenophobic as fuck to at least some extent, they just love using basic ideas and surface level things they see in western history/media, which is why they'll just have a light sword named Excalibur just cause without any attempt to reference Arthurian legend. Or literally any other random legendary sword they take from some western folklore or mythos (Durandal, Flamburge, Vorpal Sword, some other obscure Arthurian thing, etc). Japan sometimes just outright steals western names and almost doesn't learn what the fuck they mean or represent. So you just get someone named some greek name for no other reason then some writer went "That name sounds cool!". So they probably heard stories about say the catholic church doing bad things like 500 years ago and were like "Write that down!!!".
Japan if anything is at least fascinated by aspects of western culture considering how much they try to take from our folklore and mythos when they aren't wanking off samurai, yokai, or some other Japanese shit (like saying how they dindu nuffin in WW2).
Interesting fact: If Oda Nobunaga hadn't been assassinated, Christianity might have gotten more traction and respect . Dude was a brutal ruler, who had a habit of burning buddest temples and wholesale massacring people, but he harbored a fascination and admiration for the missionary's and western tech in general. To the point where he's recorded as wearing medieval armor and clothing. I hesistate to compare him to someone like Hitler or a traditional western dictator, but its interesting how such a mass killer admired and tolerated Christian teachings.
Oda Nobunaga wasn't
that special for his actions relative to the rest of his peers, he just did them better and more often then his competitors at the time, but he wasn't unique he was just more effective. Their was a story where a Takeda(?) general iirc set 3000 skulls across a battle field outside a castle and sent a message to an under maned castle that was about to be sieged saying effectively "Your reinforcements aren't coming" like a dick because he killed them prior to his siege on the castle. Also the main temple most people talk about Nobunaga burning iirc was burned less then 100 years prior so it being burned isn't
that special. Japan was crazy fucked in that time period, Oda was just the winner and thus he made the most waves so he gets the most credit for good and for ill.
The whole "demon" thing that gets used a lot nowadays in media was based on when he sent a reply letter to an opponent that effectively boils down to trash talk as he called himself the "Demon King of the Sixth Heaven" which is a buddhist thing that I forgot exactly what it means, but it roughly translates to "I'm a fucking badass, come at me."
