It is a font in which half-width alphabets are written with 15 × 7 pixels.
Therefore, the character is rough.

A font in which Japanese or half-width alphanumeric characters are written in 15 × 15 pixels.

１５×１５のピクセルで文字を書いたフォントです。

Postscript: The version made with fontforge has been released.
You can use more kanji here, and you can also write vertically.

追記：fontforgeで製作したバージョンを公開しました。
こちらでは漢字をより多く使えますし、縦書きもできます。

https://mikannnoki-font.booth.pm/items/1488587

A reproduction of the so-called "12 segment display" in a font made here. Some lowercase letters are not present as they are unable to be reproduced here.