Blue Box Ep. 18 “I Know” has Taiki engage in a badminton battle of the century against Shūji Yusa. All in spite of the fact that it’s a practice match and theoretically not as important as an actual match. Theoretically, that is. If you think about it though, it’s great prep for those real matches when Taiki gets to them.

Blue Box Ep. 18 “I Know”: Details

Blue Box cours 2 JP key art
Now the focus comes back to Taiki, since this episode is definitely all about him.

Blue Box Ep. 18 “I Know” is the sixth episode of the second cours (you can read my reviews of Ep. 13, Ep. 14, Ep. 15, Ep. 16, and Ep. 17 here) of this romantic comedy and sports anime, and is the 13th episode overall. You can read my reviews for Ep. 1, Ep. 2, Ep. 3, Ep. 4, Ep. 5, Ep. 6, Ep. 7, Ep. 8, Ep. 9, Ep. 10, Ep. 11, and Ep. 12 of the first cours here.

Said anime is the anime adaptation of the manga of the same name by Kouji Miura (I Love You, My Teacher). Telecom Animation Film (Tower of God, Shenmue: The Animation, Astro Note) and TMS Entertainment (Detective Conan, Lupin the Third, Anpanman) are both responsible for the anime, with them doing the animation, and production and planning, respectively. Netflix is the company licensing this anime for its global release.

Production Cast

Daisuke Tsukushi is the director behind Blue Box Ep. 18 “I Know”, with Yūichirō Yano himself as the storyboarder. As for Blue Box as a whole: Yūichirō Yano is the director behind the anime. Yūko Kakihara is the writer, Miho Tanino as the character designer, and with Takashi Ohmama responsible for composing the music.

Speaking of music: the second cours now features as the opening theme song “Saraba” (然らば) by Macaroni Empitsu. Meanwhile, “Contrast” (コントラスト) by TOMOO is the new ending theme song.

Voice Cast

Blue Box Ep. 18 “I Know” features the voices of Shōya Chiba (Zach Aguilar in English dub) as Taiki Inomata, Reina Ueda (Xanthe Huynh in English dub) as Chinatsu Kano, Chiaki Kobayashi (Caden Shaffer in English dub) as Kyo Kasahara, and Akari Kitō (Kayli Mills in English dub) as Hina Chōno.

Other notable voice roles in this episode include Yuma Uchida (Daman Mills in English dub) as Kengo Haryū, Shogo Sakata (Jacob Hopkins in English dub) as Ryōsuke Nishida, and Kensho Ono (Griffin Burns in English dub) as Shūji Yusa.

When and Where to Watch

Blue Box Ep. 18 “I Know” made its airing and streaming debut (aka. simulcast) on February 6, 2025. You can watch this episode of the anime only on Netflix. In fact, you can only watch this entire anime on Netflix due to it being an exclusive there.

Blue Box Ep. 18 “I Know”: Synopsis

Hina is still an important part of this episode, but the spotlight right now is on Taiki.

Alas, this second cours of Blue Box only relatively recently started its run. In fact, Blue Box Ep. 18 “I Know” only made its debut a week ago as of this writing. Thus, I will present to you Netflix’s official synopsis for this episode instead of a spoiler-filled plot summary. You can read that synopsis below:

Sajikawa High arrives for the much-anticipated practice match. As Chinatsu watches from the sidelines, she thinks about how far Taiki has come.

Blue Box Ep. 18 “I Know”: The Good

Blue Box Ep. 18 "I Know" screenshot 1
Sweating in practice makes you sweat less in real matches…or something like that.

If you’ve already watched Blue Box Ep. 18 “I Know”, then you’ll very likely agree with me that the action in this episode is one of the best parts about it. Admittedly, badminton doesn’t seem like a sport most people would associate with action at first. However, you will change your mind after this episode. Watching Taiki Inomata and Shūji Yusa playing badminton against each other is like watching a one on one duel. Only, it’s two people trying madly to hit a tiny and rapidly moving shuttlecock to where they want. The animation team at Telecom Animation Film and TMS Entertainment are really good at animating that scene, making you realize just what kind of reflexes and dexterity are needed to be able to play this sport. On top of their usual high quality animation, that is, including the amazing-as-always lighting.

Of course, that doesn’t mean that the story is neglected in this episode. Quite the contrary, Kouji Miura’s romcom story is still amazingly good. Hilarious too, even. Seriously, watching Hina do her best impression of an inchworm across the gym balcony was one of the funniest things I’ve seen in a while. It makes sense in context, really! Mostly. Maybe.

Blue Box Ep. 18 “I Know”: The Bad

Blue Box Ep. 18 "I Know" screenshot 2
Especially when your opponent is this good at the game.

Alas, sports action may not be enough for you if you’re a certain type of action junkie. There’s no blood or gore in Blue Box Ep. 18 “I Know”. There’s only sweat and youthful energy being expended here. Really, if you want bloody violence in your action, then might I suggest watching Demon Slayer: Kimetsu no Yaiba, Solo Leveling, Kaiju No. 8, DDDD, DAN DA DAN, and/or Zenshu? Those anime should have more than enough blood and gore to satisfy even the most hardcore of action junkies.

Tune back in to THS to find out more about Blue Box and other anime when we do.

Keep Reading:

Blue Box Ep. 17 “Of Course I Want To See It”: Hina Preparations [Review]