WARNING: The following contains spoilers for Sasuke Shinden: The Teacher's Star Pupil by Jun Esaka and Masashi Kishimoto, available in English from Viz Media now.
In the Boruto series, while Naruto's son shares many traits with his father, crushing on girls is not one of them. Naruto loved Sakura since he was a kid, and was often distracted by other beautiful women, but Boruto's sights are set on becoming the best ninja in Konoha. However, in the light novel Sasuke Shinden: The Teacher's Star Pupil, while Boruto does develop his first major crush, it's a rude awakening as she also turns out to be a foe unlike any he's faced before.
She is none other than Lily Himeno, a pop star who wants to have a show at the Konoha Dome to capitalize on her soaring popularity. Early on, Boruto's spotted watching her in awe on TV while his mentor, Konohamaru, nurses wounds from a terrorist attack on a train. He and Sasuke saved civilians, but the entire squad of killer shinobi either died in the fight or committed suicide. However, Boruto, as much as he cares for his teacher, is enamored by Lily, even though he denies it.
Later on, he, Mitsuki and Sarada are commissioned by Lily, who's come to Konoha in disguise, to protect her from the same ninja cult that hurt Konohamaru. She convinces Boruto to use his transformation jutsu to pretend to be her and he goes along. This surprises Sarada, as she thinks they should inform their seniors, but Boruto's totally smitten, even doing the job for free, claiming it'll impress their teachers.
However, his body gets possessed on-stage and the ruse is exposed, with Sasuke taking the rap for closing the show down by using his Susanoo. It's a failed attempt to kill Lily/Boruto by the same cult, whose members died at the show, leading to Sasuke revealing Lily as the young rich girl on the train who was targeted in his and Konohamaru's mission. Boruto, though, can't get anything out of the imprisoned Lily, as she's confirmed as part of this Purple Moon cult, yet also someone they want dead.
It comes to a head in the finale where Sasuke and the kids try to stop the cult from blowing up a ship outside Konoha, only for Lily to escape and attack them. She once more uses her bio-electric manipulation to possess Boruto's body to try to get him to kill Sarada. However, with the help of the Uchihas, she fails. Still, Boruto can't figure out her motives, not until the very end when all enemies are taken down and he saves Lily as the ship blows up. He doesn't care that she tried to shoot him, or that she's part of a terrorist faction or that she took over his body; Boruto just hates seeing someone like him brainwashed.
This is when Lily admits her dad, the leader of this group, died on the train. He wanted her dead for defecting -- she was supposed to infiltrate Konoha and cause chaos using bombs, but she left her home, opting to use her music career instead. The impersonation and dead assassins at the show were meant to paint Konoha as an unstable place which would have sullied its good name. It's a much more subtle plan than outright bombing the place.
However, her people, from the Land of Water, never agreed with her pacifist perspective, which is why they tried to kill her on the train. To them, murder works better and faster than PR. It's also why she hijacked the boat mission and tried to cause an explosion which, while it wouldn't have killed innocent civilians, would also have proven Konoha was dangerous.
Lily was simply looking for a solution that didn't spill innocent blood, which she'd admit on TV days later to clear Konoha. But from all this, Boruto learned about keeping his guard up and not give his trust away so easily, as everything his dad and Sasuke worked for almost got taken away -- all because a girl stole his heart, mind and, literally, his body. He's never fought anyone as cerebral and subtle as Lily, who was truly a puppet master that clouded his judgement. But disappointment is a great teacher, and Boruto doesn't intend to make such rookie mistakes again.
