I don't know if there will be a second tome but I hope they will make a second one.
I like the game and it has a good story.
The title is blood and cold (sang-froid) if that is what you meant about the meaning of the title.

The title is sang-froid, an expression (because of the " - " ), meaning having guts or keeping your cool. For exemple, "avoir le sang-froid dans une situation périlleuse" pretty much means keeping your head straight when in a dangerous situation. Though blood and cold could also be a valid meaning because of the colors of the title.

My qyestion was actually more about the ending ^^' Is the story a complete one in this game, or does the Tome 1 suggest I'll have to get Tome 2 to unravel everything ?

Giving how the story end, my answer would be yes

But given how...problematic this game can be sometimes(strange occasional bugs, inadequate traps for most of the game), and the relatively low interest this game managed to attract, probably no