Solomon's story in the series shows his struggle to be taken seriously in his career while also highlighting the differences between him and his grandmother's generation. Another aspect the series explores is the rekindling of an old love interest, Hana.
Hana is referenced multiple times in the series, first in an interaction between Solomon and Etsuko (Mozasu's girlfriend and Hana's mother). In this tender scene, it's revealed that Solomon loved her and still thinks about her even though she's missing. Throughout the series, Hana calls Solomon at work from an undisclosed location, and the two keep in touch through brief phone calls.
While Solomon is single in the TV series, in the book, he's in a committed relationship with Phoebe, a Korean American whom he meets while attending Columbia University. Despite their serious relationship, the couple ultimately break up after relocating to Japan.