It's apparently a historical cultural thing for Japanese, which contains many interesting and overlooked quirks.
For example, did you know that samurai kohei (Juniors) are encouraged to have "intimate" relationships with their seniors? It's not as simple as that but it gets the idea across...
That's only one of many, and one of the milder quirks.
I'll also raise the point that the Kraken <> virgin connection as imagined by the Japanese has more history then Cthulhu.
Seriously, what's a kraken going to do surrounded by virgins on the battlefield?
Sacrificing them in a bloody frenzy isn't all that much better in my mind, messier in fact!
P.S. I'd go all the way and give kraken seduction.