Lets see - from wiki:
En (Н, н) is a letter of the Cyrillic alphabet. It represents the consonant /n/ unless followed by ь or any of the palatalizing vowels when it represents /nʲ/. It looks exactly like the Latin capital letter H, but it is derived from the Greek letter nu (Ν, ν).
Coincidentally, the letter I (И, и), which looks like a backwards N, derives from Η (eta) while the letter En (Н, н) derives from Greek Ν (nu) which looks like a backwards Cyrillic И.
Sha (Ш, ш, italics: Ш, ш) is a letter of the Cyrillic alphabet, representing the consonant sound /ʃ/ or /ʂ/. It is roughly equivalent to sh in English, ch in French, sch in German, ش in Arabic, ש in Hebrew, ş in Turkish, or sz in Polish. In most Latin-alphabet Slavic languages (Czech, Slovak, Serbian, Slovene, Croatian) this sound is written š, and linguists have adopted this symbol to transliterate ш into the Latin alphabet.
The printed Sha looks something like a W or, more exactly, like an E rotated to the left 90 degrees. It is used in virtually every national variation of the Cyrillic alphabet, for Slavic and non-Slavic languages. In mathematics, the Tate-Shafarevich group is denoted Ш, a notation first suggested by J. W. S. Cassels. (Previously it had been unimaginatively denoted TS.) In a different mathematical context, some authors allude to the shape of the letter Sha when they use the term Shah function for what is otherwise called a Dirac comb.
The sound /ʃ/ is described as a voiceless postalveolar fricative. The postalveolar fricatives are the major reason why the Glagolitic and later the Cyrillic alphabet were invented, because they cannot be written with a simple Roman or Greek letter without diacritics or digraphs. Slavic languages are rich in postalveolar fricatives and affricates, and Sha is one of the most typical letters of the Cyrillic alphabet.
Sha has its earliest origins in Proto-Canaanite Shin and is linked closely to Shin's Greek equivalent: Sigma (Σ, σ). (Note the similar form of the modern Hebrew Shin (ש) which also derives from the same Proto-Canaanite source). Sha already possessed its current form in Saints Cyril and Methodius's Glagolitic alphabet. Most Cyrillic letter-forms were derived from the Greek, but as there was no Greek sign for the Sha sound (modern Greek uses simply "σ" to spell the sh-sound in foreign words and names), Glagolitic Sha was adopted unchanged. There is a possibility that Sha was taken from the Coptic alphabet, which was the same as the Greek alphabet but had a few letters added at the end, including one called "shai" which somewhat resembles both sha and shcha (Щ, щ) in appearance.
So maybe nearer Nasha than Nasa.
