Japanese: こんにちは
Hiragana: こんにちは
Katakana: コンニチワ
Romaji: Konnichiwa
You can also find it written in kanji, but it's not the standard way:
Kanji: 今 日 和 (konnichiwa) - this is a literal translation of the word, meaning "today's peace" or "today's harmony."
It's important to note that while the kanji form exists, it is rarely used in everyday conversation. The most common way to write "hello" in Japanese is using hiragana.