Sasmira

Le temps irrevocable a fui. L'heure s'achève... Mais toi, quand tu reviens et traverses mon rêve, tes bras sont plus frais que le jour qui se lève, tes yeux plus clairs... A travers le passé, ma mémoire t'embrasse...

Sasmira is a French-Belgian comic book series by Laurent Vicomte. The first tome was published in 1997, and it took the author until 2011 to finish the second one.

Stan is a young Parisian orchestra conductor. One day, in front of his door, he finds an old woman who tells him a mysterious sentence and gives him a beetle-shaped gold ring before dying. He becomes obsessed with finding out who she is, and traces her back to a now-abandoned mansion in the French countryside.

His girlfriend, Bertille, concerned that his single-minded quest is jeopardizing their relationship, decides to help him in order for him to move on eventually. They both go to the mansion, where Bertille puts on a period dress she found. In a room, they see a woman in a strange metallic sarcophagus, apparently in a state of suspended animation. While a storm rages outside, they find refuge in a cellar, and black out after having sex.

When they regain consciousness, they are in a bed. They are still in the mansion, but have somehow ended up in the year 1907...

Tropes used in Sasmira include:

Blind Without'Em: Bertille is very short-sighted and only sees a blur when not wearing her glasses.
Cloudcuckoolander: His quest turns Stan into one.
Costume Porn: The period clothing is drawn in lavish detail, down to every last frill.
Double Entendre: Stan describes an attractive Lady in Red while ostensibly talking about wine.
Dramatic Thunder
I Am Not Shazam: None of the characters introduced so far is named Sasmira, though one suspects it's the name of the mysterious dark-eyed girl.
Impractically Fancy Outfit: To Bertille, this is what Belle Epoque ladies' wear feels like.
Landmark of Lore: It's hinted that the glass pyramid at the Louvre may have longevity-enhancing properties.
Literal-Minded: On several occasions, a character will take literally a figurative turn of phrase by another character.
Of Corsets Sexy: Bertille gets to wear a tight-laced corset in 1907.
Scenery Porn: The 1907 scenes are nicely drawn. The chateau in said scenes also looks considerably better than its present day form.
She Cleans Up Nicely: Bertille's default outfit is a plain T-shirt and jeans, and her looks are considerably improved when she dresses up.
- Though it comes off pretty quickly following the sex scene.
Tall, Dark and Bishoujo: The mysterious dark-eyed girl at the country house.
The Little Black Dress: In order to catch Stan's flagging attention, Bertille gets talked by her best friend into putting on a little black dress. It doesn't work but she does look gorgeous in it.
Time Travel: Whether of the Stable Time Loop sort or not remains to be seen.
Trapped in the Past: Stan and Bertille had no intention to travel back in time, and have no idea how they ended up in 1907.