After moving to the seaside town she had visited in her childhood, Hina Tsurugi looks forwards to a peaceful life in high school, where she intends to join the Handicrafts Club and make new friends. While exploring the town prior to the start of term, she encounters an older girl who appears to be suffering from heat stroke. Upon closer inspection, it turns out the older girl had actually been fishing. She introduces herself as Yūki Kuroiwa, and invites Hina to give fishing a go. When Hina unintentionally catches an octopus, Yūki sees an opportunity to strong-arm Hina into joining the Breakwater Club, which focuses on fishing. While Hina initially is reluctant to join the Breakwater Club, she learns that her childhood friend, Natsumi Hodaka, is also attending the same high school and is convinced to at least giving fishing a chance before deciding which club to join. Along with the quiet but knowledgable Makoto Ōno, Hina discovers that fishing is remarkably fun, learning how to catch everything from Horse Mackerel Fry to Whiting with her newfound friends. From selecting the right equipment, to preparing their catch for consumption, Hina becomes enthralled and slowly begins to overcome her fear of aquatic life as she becomes accustomed to the eccentric, but exciting Breakwater Club.
Diary of Our Days at the Breakwater (Houkago Teibo Nisshi, literally "Afterschool Embankment Journal") is a Slice of Life Four-Girl Ensemble manga about recreational fishing. Written and illustrated by Yasuyuki Kosaka, the manga began serialisation in Februrary 2017 in Young Champion Retsu magazine. Because of flooding in Kosaka's area, it was announced that the manga would go on a brief hiatus in July 2020. While the manga continued subsequently, a second delay was announced, with the manga going on a hiatus starting December 2020. Diary of Our Days at the Breakwater received an anime adaptation in April 2020, which was produced by Dogakobo and' is licensed by Funimation. During its airing, the COVID-19 pandemic resulted in delays to its production. After episode three aired on April 15, the series was put on hold until July. The first three episodes were re-broadcast starting July 1, and the fourth episode aired on July 28.
A television drama is set to air in Q3 2023.
Diary of Our Days at the Breakwater provides examples of:
- Accent Adaptation: The english dub gives everyone but Hina a Southern accent.
- Bland Name Products: The club uses Dulp! lures as opposed to the actual Gulp! lures.
- Brilliant, but Lazy: While Yūki is highly experienced in fishing, in addition to being very knowledgable about the tools and marine life, she tends to avoid any activities if it involves too much effort, leaving Hina and Natsumi to do the more mundane chores if she can get away with it. However, her casual and relaxed mannerisms makes her suited for introducing Hina to fishing, as well.
- Cute Little Fangs: Natsumi has a fang visible on the left side of her mouth.
- D-Cup Distress: Makoto tends to become embarrassed whenever her bust is mentioned. When Hina and Natsumi discuss jackets during the fourth episode, they assume that Makoto's chest is making it difficult for her to find a good jacket, and she immediately corrects them, saying it's her height that makes it tricky.
- The Danza: In-Universe (well, out of universe, but in the manga's omake) Natsumi's voice actress calls attention to the fact that she has the same name as her character and says it is "destiny".
- Diegetic Soundtrack Usage: In episode 6, Hina hums the OP theme while knitting in her bedroom.
- Epic Fail: While learning how to cast a line during the second episode, Hina struggles and ends up getting her line caught on Natsumi's skirt on no fewer than three occasions. Even when Natsumi decides to back away and take cover behind a statue on the breakwater, Hina still manages to hit her anyways.
- Expy: Makoto Ohno resembles Sumika Murasame.
- The Faceless: In chapter 46, Yuki tries to help Makoto get over her fear of the ocean. Makoto takes off her glasses, leading Yura to break the fourth wall and make a comment on how she's showing her face for the first time. She then hands Makoto goggles and a snorkel, which immediately covers Makoto's face again.
- Fishing for Sole: While fishing for flathead, Hina reels up clumps of seaweed and initially assumes she's caught something.
- Food Porn: It's a manga about seafood, so of course it devotes time to making seafood look good. But, unfortunately for your appetite, the author expends just as much effort on illustrating the seafood before it becomes seafood. As in, detailing both the nasty sea critters and the gory ways they're butchered and prepared.
- Four-Temperament Ensemble:
- Sanguine: Hina is the wide-eyed beginner, ever ready to learn even if she finds herself overwhelmed at times.
- Choleric: Natsumi is energetic, pushy and excitable, but otherwise passionate about fishing
- Phlegmatic: Yūki is the laid-back leader club president with a go-with-the-flow attitude and marches to the beat of her own drum
- Melancholic: Makoto is taciturn and shy, but when she gets excited, she runs her mouth off with explanations on all things related to fishing.
- Forgotten First Meeting: Hina and Natsumi were childhood friends, but Hina's forgotten all about it in present day, while Natsumi and both of their parents all remember each other clearly, it's also theorized by Yuki that she also could've known Hina back then since it lines up with how long she's known Natsumi.
- Real-Place Background:
- Most of the events in Diary of Our Days at the Breakwater are set in and around the town of Ashikita in Kumamoto.
- The girls visit Yamamoto Fishing Gear Centre’s Main Store in Kumamoto during the fourth episode, which is about two hours away from Ashikita by train.
- In episode seven, Natsumi suggests to Hina that they study at her place, a Western-style restaurant that is modelled after Grill Kakashi in Hitoyoshi.
- Repeat Cut: Three separate cuts are used to emphasise the moment when Hina catches Natsumi's skirt with her fishing rod.
- Rod And Reel Repurposed: Hina's first efforts to learn how to cast a line results in her catching Natsumi's skirt. Yūki repurposes a buoy to help Hina learn how to aim, and with time, Hina begins to improve.
- Scary Shiny Glasses: Makoto's glasses are reflective and always conceal her eyes, but despite her appearances, Makoto is the gentlest member in the Breakwater Club.
- Shout-Out: A Japanese ad for chapter 9 parodies the poster for Ghostbusters (2016), with Natsumi slinging her rod over her shoulders just like Kate Mac Kinnon's character.
- Sympathetic Wince: In chapter 48, after Makoto uses a Shinkei-Jime to stab a fish between the brow and break its spinal cord, she turns around and sees every single other girl clutching her forehead and grimacing.
- Troll: Yūki is fully aware that Hina is afraid of touching fish and insects, so she goes out of her way to frightening Hina with them from time to time. However, Yūki also explains that it is only with exposure that Hina will be able to get over her fears.
- Unwitting Instigator of Doom: In chapter 43, it's revealed to the audience that the reason Hina is terrified of animals is because Natsumi tried to show off her dog and cat, only for both of them to scratch Hina. Hina doesn't remember that it was specifically Natsumi's pets, and Natsume — who forgot all about the incident until Hina brought it up — elects not to tell her.