it's about the works of Suzuki Shosan (鈴木正三), samurai Zen priest who lived 1579- 1655.
Turns out he was highly critical of Christianity, publishing a book (evidently the government liked it enough to publish it), called Ha Kirishitan (破切支丹), which has the nice passive title "Crush Christianity."
From the tiny snippet I've been able to read online, though, it's as harmless as Dawkins in its arguments.
Except for that "Southern Barbarian" thing. But evidently we were all barbarians to them.
Anyhow, evidently he's buried near Takao-san, near Hachiohji, which happens to be a suburb of Tokyo.
And he's noted at that website for his publication of 破切支丹.