In Japanese you can express emotional nuance or stress via emphasis particles that may equate to a vocal exclamation mark or emoticon.
We shall in this short explanation look at the most commonly used.
Ne (ね), Na (な) and No (の):
This one is a "softener" to expressions and appears in polite, amiable or in most cases female language versus that of the male na - which asserts forcefulness or just roughness. Thus, you would not say "soudesu" (そうです, "is that so") with na added to it in regular polite parlance, but with ne since polite language is all about appearing as non-confrontational as possible. No unless elongated into nou (のう), is commonly found amongst all ages in Standard Japanese with female language, but the latter appears mostly in dialects and the generic old folks sociolect.
Yo (よ) and Ya (や)
Adds assertion, in a neutral degree and is the most commonly seen with all genders. Adding ne or na to the end of it gives more power to it, but also makes it more informal. Ya is typically older varieties of language, but when used in the Kansai dialect it is a copula derived from dearu (to be).
The most forceful if aggressive of the emphatic particles and is mainly used by males. The variant zoi (ぞい) is a standard part of fictional oldster talk. Combining this with yo creates zoyo which is markedly also part of the vocabulary of older characters.
Decisively female in modern Standard Japanese, but gender-neutral in older dialects. The variant wai (わい) is even more old-fashioned.
All of these can however be combined as one pleases, since language is ever immutable, but nevertheless take heed not to sound all too old fashioned or hip.