Can you tell me what this says?

Well, I can confirm that it’s Japanese. Also, from googling it and looking at various ways in which it’s used (plus hit counts [3,890,000]), looks like it means ‘I love you’ and is pronounced as ‘aishiteru” (see this for confirmation).

i can recognise a chinese character there.

The first character is ‘Ai” means love.

Translation: Japanese » English
愛してる Aishiteru
One of the most popular phrases in any language is probably “I love you.” In Japanese, “love” is “ai （愛）,” and the verb form “to love” is “aisuru （愛する）.” “I love you” can be literally translated as “aishite imasu （愛しています）”. “Aishiteru （愛してる）,” “aishiteru yo （愛してるよ）” or “aishiteru wa (愛してるわ, female speech)” is normally used in conversation. However, the Japanese don’t say “I love you” as often as Western people do, because of cultural differences. I am not surprised if some Japanese say that they have never used these expressions in their life