Based on the structure and the popularity of certain media tropes, I suspect you are looking for an article about a character archetype or a specific drama/CD/manga related to the phonetic name and a theme involving a hated ex-boyfriend. The "Make..." likely suggests either "Make Up," "Make Me Regret," or "Make Him Pay."
The name "Nagi" suggests calmness (凪) – a deceptive stillness before the storm. "Hikaru" (光) means light – the blinding, misleading glow that attracts the protagonist before she realizes it burns. Nagi Hikaru - My Ex-Boyfriend- Who I Hate- Make...
Since "Nagi Hikaru" does not directly match a famous single mainstream character (though "Nagi" is common in Hayate no Gotoku! and The World God Only Knows , and "Hikaru" is common in Ouran and Hikaru no Go ), I have constructed a based on the most likely interpretation of your keyword: The psychological and narrative archetype of the "Hated Ex-Boyfriend" in Japanese media , using the placeholder name Nagi Hikaru as our case study. Based on the structure and the popularity of
She stalks his social media. He posts a gym selfie with the caption "New year, new me." She eats ice cream. The hatred crystallizes here. Since "Nagi Hikaru" does not directly match a
She learns Krav Maga. She publishes that novel. She walks into the office reunion wearing red. Nagi drops his drink. The silent "I won."