Here is Motomura Aoi’s confession, with English subtitles, from the video games AKB 1/149 Renai Sousenkyo Love Election.

There is nothing in particular that sticks out here in terms of grammar or vocabulary; however, please note Aoi-tan’s occasionally use of Hakata dialect (博多弁).

ただの友達やけん　→　standard dialect is: ただの友達だもん。

The ending もん is kind of interesting. Similar to how よ or ね changes the tone of the sentence implicitly, adding もん seems to (in my experience anyway) express a sense of dissatisfaction. Please also that note that 〜もん is a casual from of 〜もの. In this case, Aoi is expressing here dissatisfaction that you two are only just friends 😉

Lastly, she says the ever common phrase: よろしくお願いします（yoroshiku onegai shimasu). This phrase is ever problematic, precisely because there’s no real English equivalent, and can vary widely depending on the context. In this instance, having just acceptance her confession, one can infer that she is asking for your kindness in your upcoming relationship. So, I translated this as: “Please be kind to me”.

Here is the transcript with inline translations:

もう行かなくちゃ。公演あるし。
I have to go. There’s also a performance.

今度いつ会えるかな？
I wonder when we’ll meet again?

あー、帰りたくないな。
Ah… I don’t want to go home.

ねぇ、一緒に行こう？
Hey… shall we go together?

無理だよね。ただの友達やけん。行くね。
That’s impossible, right? Since we’re just friends. I’m going, okay?

あのね、やっぱり、あなたの彼女にしてください！
Umm, hey. Actually… please make me your girlfriend!

Acceptance!

よろしくお願いします！
Please be kind to me!