Just a few suggestions on style. No big mistakes in here.

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How to write something in a romantic manner in English

A couple of months ago, I came across a certain met a girl at on some SNS site, and made a habit of talking with her over skype a couple month ago. She is really nice and always cheerful. Now, the sessions with her have become an important part of my daily life.

Tonight, she has a party with her colleagues, and I'm afraid we cannot have a session because she'll be tired and I don't want to bother her. I miss her Although I talk with her almost everyday, I miss her already, so I'd like to kill the time by listening to her favorite song "The Lazy Song" by Bruno Mars. The song reflects what I'm feeling now. We both actually love spending time in a "goro goro" manner. "Goro goro" in Japanese stands for being lazy and relaxed.

Hmm... After all, I'm feeling a sort of frustrated because it's quite difficult for me to write something romantic in my private diary. I'm, to some extent, accustomed to describing something technical or logical things at work, and I'm convinced that English language is the best tool for the purpose to me that, but However, I cannot in a write anything romantic manner. I myself have a the feeling that I totally lack in the ability to maneuver effectively use metaphors in an effective manner in English.

Could anybody give me some advice on how to write something in a romantic and enthusiastic manner in English, or any recommendation for some good books in English on the subject? I'd like to keep a diary about what I feel everyday more lively to such an extent so that I can reproduce my memory remember 10 years later (Am I too ambitious?). Note that my nature is, as most Japanese are, very introversiveted, and that my private diary is just for self-satisfaction I will never share what I write in my private diary.

I'd really appreciate any corrections and comments on my entry.

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Now, to answer your question, I do not think you will find such a book. Metaphors are likely related more to the cultural context of the langauge than to its structure or grammar. So the best way to learn about metaphors is to become adroit at recognizing the cultural connotations of the language productions. That means read and speak a lot. No, much more than a lot. Remember, a good metaphor can very rarely be translated successfully. So you must think directly in the target language.

Short term solution. Try reading some love poetry. Some may rub off on you. :-)

Also, remember you can be romantic without using fancy methaphors. I am sure you can express yourself effectively, with the right amount of emotional impact (and hopefully exacting the right response), while keeping it simple. Especially in English. I can even risk saying that if you manage to feel too direct, almost pushy, you are likely on the right track. Based on the standard usage, most English native speakers expect one to be quite direct, way much more than a typical Japanese may feel comfortable with. So yes, do go out of your comfort zone (without becoming coarse, obviously).