Happiness is 幸せ and happy is 嬉しい
I
I
幸せな Shiawase na
Tanjoubi omedetou kevin
jherick
I am happy to provide a recommendation letter for you.
I am happy to provide a reference letter for you.
Otanjou-bi Omedetou Gozaimasu!
Z. single roman letters can not be written in Japanese
If you mean how to write 'Joseph' in Japanese : ジョセッフ (jo se'ffu) is the answer.
As in you write a letter to someone? Tegami.
you write sweetly and nicely to make her feel warm and happy