Summer anime season 2016’s Orange is based off a popular sci-fi/romance/slice-of-life manga, which has also been adapted into a live-action film. The concept of time travel and changing past regrets is a popular theme in the latest anime seasons, with shows like Erased and Re:Zero taking advantage of temporal disturbances to great effect. In Erased , the main character is thrown back mysteriously after disaster; in Re:Zero, our main character is thrown back in time after each death.

In Orange, the “time travel,” if you can call it that, is much simpler. The only thing traveling back in time so far is a letter, from main character Naho Takamiyato her high school self 10 years ago. The close of the mysterious letter reveals that she wishes her younger self to avoid a series of regrets, the worst of which is the death of her beloved friend Kakeru.

The goal is still the same as in Erased and Re:Zero: to prevent a ruinous disaster. Erased is a thriller, so its disaster is the murder of a little girl; in Re:Zero, which is a straightforward play on gaming and fantasy tropes, the main character simply fights not to die in a strange world.

Orange isn’t a thriller nor a sexy play on tropes; because it’s a slice-of-life, it moves more slowly and more gently, and because it’s a romance, characterization is key. Its premise is arresting immediately, not the least because of the lack of magic or sci-fi throughout what is otherwise a normal high school anime.

Naho’s letter states factual events that Naho confirms throughout the day: she oversleeps for the first time, there is a new transfer student named Kakeru, he will be seated next to her. All of these things happen. The letter writer states that she will list the choices she wants young Naho to make, so that grown Naho’s regrets and mistakes never come to pass. While saving her friend is critical, grown Naho also wishes to save herself the gnawing pain of regrets she’s held onto for ten years.

Orange is produced by TMS Entertainment, which has been in business since the ‘60s and is responsible for hits like Yowamushi Pedal, D.Gray-man and Detective Conan. Their experience shows, with character models consistent with the manga’s charming art style. Still-frame shots are intelligently used during montages, leaving the budget plenty of room for competent animation in other scenes.

The slice-of-life mood is apparent in the beautiful scenery shots and mellow background music, as well as the cast of friendly characters rotating around Naho. Small conversations about mundane matters, like Naho talking to Kakeru about her gym shoes being too small, help establish character and mood as well. Things feel sleepy and calm, with an undercurrent of tension: we know a disaster is incoming.

The letter writer never says what will happen if their directives aren’t followed. For example, the writer instructs Naho not to invite Kakeru to walk home together as one of her bullet points. But Kakeru seems to really enjoy meeting all of Naho’s friends, and Naho concludes that she’s satisfied with having invited him. When she checks her diary against the events predicted in the letter, she notes that all the day’s occurrences were accurately noted in the letter. But the next day at school, Kakeru is absent, and he doesn’t come back for weeks.

The next directive asks her to accept becoming a pinch hitter for the softball game. At first she refuses, and another friend cheerfully agrees to take her place The letter tells Naho her friend will strike out and they will lose the game. Naho realizes that her fear of doing something she knows she is capable of will cause her friend to bear the responsibility of her team’s loss, so this time, she follows the letter’s direction. She hits the ball and her team wins.

Orange has a powerful, compelling theme: not wanting to carry regrets with you for years and years. Everyone can relate to the wisdom of hindsight, the feeling of wanting to spare your vulnerable young self the pain of mistakes as well as wanting to spare yourself the sting of regret. The uncanny letter from the future is a great concept, and the stakes are high - not only Naho’s future, but that of gentle, affectionate Kakeru as well.

Should you watch Orange?

If you’re not all tuckered out on time travel plots, Orange looks like one of the most appealing summer 2016 anime so far. If you love romance, sci-fi themes or a good slice-of-life that doesn’t cross into moe-bait territory, Orange looks like a great addition to your queue.

Orange is simulcast on Sundays at 12:30 p.m. on Crunchyroll here .