Interminable

Both Thai BL dramas feature BillyBabe as the main leads and have strong Thai supernatural themes and folklore. The Sign is an action series with them acting as detectives while Interminable is a historical drama.

They are both historical Thai BL dramas about fated lovers set around the same time period (1910s~1920s). Both have an upper class character together with a lower class character and struggle with societal acceptance of a male-male relationship during that time.

Both are fated lovers that ended tragically in their past lives and are restarting their love again in this current lifetime after their past memories are revived.

"Interminable" and "I Feel You Linger in the Air" are historical drama series center around an estate that is significant to the protagonist transmigrated either from the past or the future. Either way, the protagonist has an infinity with the owner of that estate, a promise awaited to be fulfilled.

-Thai Bl
-Reincarnation
-Both have historical plots/aspects
-Female lead trying to get between the two

Overall, the two dramas have similar vibes/atmosphere as well as plots.

-Thai Bls
-Historically centered plots

Both dramas involve a ghost MC who can disappear and reappear, Both have complex issues around ghosts and 'moving on'.

Interminable is historical and involves ghosts that did not move on or reincarnate, waiting for the other people in their lives to find them again.

Something in my room is present day and involves uncovering the mystery as to why the MC died and sorting out his unfinished buisiness.

Both have ghosts and folk law as well as traditional Thai aspects.
Both have supernatural events.
Both are about rebirth and have characters that are reborn.

Both of the series are a period drama, more of a Lakorn, one of the differences is that LITM is set in the 1960s while the other is set in the 1940s, there's also the presence of the tragic and melodramatic elements,

Both the series are a period drama, one is set in the 20s, the other in the 40s, "I Feel You Linger in the Air" have a time travel theme, while "Interminable" have a reincarnation theme.

Both dramas have similar couple dynamics and sensuality. Both actors are very comfortable with each other and depict realistic scenes of romance and bonding. The series are high quality with lovely costumes and cinematography.

Both are historical Thai BL dramas with a past and present timeline that features a love story between a human and a ghost that is trapped inside an old house.