[nneonneo]

Japanese uses three distinct character sets in writing: Hiragana (a syllabary), Katakana (another syllabary) and Kanji (Chinese characters). Hiragana and Kanji are usually used together to write native Japanese words, whereas Katakana is used almost exclusively for loanwords.

Katakana syllables are either bare vowels, or consonant+vowel (with few exceptions), meaning that transliterated words must be contorted to fit the syllabary (the "lossy algo" referred to by the parent comment). So, something like "kernel" in English becomes kaa-ne-ru, and "subsystem" becomes "sa-bu-shi-su-te-mu".