For researchers

My name is Kazune Takahashi. To obtain my research information, please visit the following sites.

This website is maintained by Kazune Takahashi. Almost all entries are in Japanese and most of them are not directly related to my research.

I am not currently in the teaching profession. Thus I should be called “Dr. Takahashi”, “Takahashi-san”, “Mr. Takahashi” or simply “Takahashi”.

In Japan, many people are called “Takahashi” as their family name, but my first name “Kazune” is a scarce name. So you can distinguish my works from others’ by my full name “Kazune Takahashi”.

About this site

Basic rules

This site mainly consist of entries of my diary and memo of my competitive programming.

The site name “Unhappy Go Lucky!” is the title of 『あんハピ♪』. I like this phrase.


  • Contest: my reviewing competitive programming.
  • Material: materials written by me.
  • Diary: my entries of my diary.

About me


My ID almost anywhere on the Internet is kazunetakahashi. I currently continue to use and update Twitter, AtCoder, GitHub, Researchmap and LinkedIn.

Each of the icons is either of the followings.

The Header of Twitter is as follows.

  • “Magia Record: Puella Magi Madoka Magica Side Story” (Official)
  • “Pokémon: Let’s Go, Pikachu! and Let’s Go, Eevee!” (Official)

Favorite Quotes

Let justice be done, though the heavens fall.

Nothing is true. Everything is permitted.

In solitude, where we are least alone.

Favorite things

Favorite animes

I had been watching almost all of the new TV anime in 2008-2018. I’ve watched animes after 2000. In 2019, I quitted watching animes as my hobby but watch them when I am available.

I prefer almost any animes: 男性向け、女性向け、子供向け、健全なもの、不健全なもの、ホラー、暴力を伴うもの、サスペンス、探偵、平和なもの、日常系、アイドルもの、恋愛もの、ラブコメ、 SF 、ファンタジー、ロボットもの、バトルもの、コメディ、スポーツ、戦争、歴史もの… I accept all of them if they are interesting.

Favorite games

I have been playing video games since I was three years old. I enjoy playing various games. I am not so good at battle games or speedruns, but I am very good at some kinds of games. In fact, I am a YouTube Creator. Note that the channel is not related to my real name. Stop Google suggestion with my name!

I have Nintendo Switch, XBOX ONE, New Nintendo 3DSLL, Wii U, iPad Pro in my house now. Before I entered the university, I enjoyed playing arcade games.

Favorite foods

In Japanese, 寿司、鰻の蒲焼き、ビーフステーキ、ローストビーフ、鶏もも肉の唐揚げ、ハンバーグ、紅鮭、鯖の塩焼き、ほうれん草のおひたし、にんじんのグラッセ、きのこサラダ、ゆで卵、納豆、豚汁、赤いきつね、ボンカレー、みかん、パイナップル、りんご、キウイ、バナナ, etc.

I don’t drink alcoholic drinks. I don’t smoke.

Favorite subjects

I love Mathematics and Programmings. I like studying itself.

The most favorite subject is mathematics. My interests include partial differential equations and real analysis. Of course, I also like algebra, geometry, complex analysis and other fields of analysis. I have not hated math once for ever.

I studied physics and information sciences when I was with the junior division of the faculty of arts and sciences.

I realize that I am a programmer or a developer, not an engineer. My favorite language is C++ (C++11, 14, 17, 20, …) and Ruby.

I also like to study English. I am not a professional of English but I continue to study it. I enjoy solving the center exams and the Todai exams and the Todai open exams.