Kokoro, in the simplest sense, means heart. There is a clear distinction between kokoro (the romantic notion of a heart) and shinzou (the physical, beating organ in your chest.) Think of kokoro as the heart you make with your hands for cute pictures and shinzou is the image of a heart you’d find in anatomy class. Kokoro means heart, emotions, even convictions that are strong enough to guide a person. In fact, kokoro carries a connotation of humanity or the soul. In romance anime, be it gay or straight, kokoro is often mentioned when one character comments on the erratic beating of their heart, or to mention where the person of their affections exists (in their kokoro). Not as commonly, kokoro are mentioned in the context of souls, with some evil antagonist stealing hearts and thus the very nature of one’s humanity. But back to the cute stuff! Shoujo(girl), shoujo-ai (girl-love), and shounen-ai (boy love) anime often utilize the word kokoro, especially in shows with a slightly more serious nature.

Tachibana Mei is a gloomy high school student who shuts herself off from her classmates. She’s not shy, she just doesn’t see the point in becoming close to people who will only turn around and betray you when it suits them. She’s quite content with her hermit life until her path crosses with Kurosawa Yamato, an extremely attractive and well-liked guy. The two form a strange and complicated attraction to each other, but being so very different causes a lot of problems for them. Will Mei be able to say the words in her heart or will Yamato never hear her say “I love you”?

Sukitte Ii na yo is a great show that talks about kokoro. It’s romantic, it’s dramatic, and it’s exciting; all things associated with the metaphorical heart! One particular scene that shows the nature of the heart as a romantic idea rather than a blood-pumping organ is between Mei and Kai. Kai has accidentally upset the girl he likes and tries to explain to Mei that his word choice may have been clumsy but to ‘kokoro kara omottenda.’ (I thought that from my heart). Obviously, he doesn't consider his heart capable of sentient thought but is expressing the idea of true and honest feelings stemming from his very being. The use of kokoro is to express your awareness of deep and personal feelings, and to express a sincerity and honesty.

Doki doki is the sound of a beating heart, similar in English to ‘ba bump’ or ‘lub dub’. It’s the excitement before a big game, or the ensuing rush of emotion when your crush holds your hand. I’m sure we’ve all heard it, watching with gleaming eyes as our favorite oblivious characters struggle with their emotions. Far more common than being said, however, is seeing it in manga and even anime. You’ve probably seen doki doki written as a sound effect even if you couldn't read it if you've ever binged romance manga of any genre. Doki doki is an onomatopoeia, and Japanese is rife with them! Adding the verb suru (to do) turns these sounds into verbs and they are commonly used. People are more likely to say ‘doki suru’ than ‘doki doki’ because the former is more formal and the latter sounds less proper, almost child-like.

Doki doki is a sound effect resulting from an emotional reaction rather than a physical one. You wouldn’t say your heart went doki doki after running a mile. You would say it if the girl you liked flashed you a cute smile she won’t show to anyone else (and that might also result in a nosebleed). You can feel doki doki in anticipation of a coming event as well, such as having to perform or give a speech to a large audience. While doki doki is often used to express an extreme happiness and excitement to some stimuli it can also connote apprehension and nervousness.

Serinuma Kae is an unabashed and confident fujoshi. She’s a big girl and is sometimes even made fun of for her looks, but she couldn’t care less. After all, a cute guy flirting with her would be a waste when he could be flirting with another cute guy instead! However, after experiencing extreme trauma from one of her favorite shows, Kae holes herself up in her room and refuses to eat. When she emerges, her cuteness has exploded and now the guys she was coupling together in her mind are trying to ask her out!! While her friend Mutsumi-senpai treats her most normally, guys that were either indifferent or even rude to Kae are now trying to win her favor. Kae was just fine with the way things were, and this new set-up of guys becoming rivals instead of growing closer to each other is a fujoshi’s worst nightmare! Kae and her male suitors want very different things, and they are about to learn a lot from each other.

Watashi ga Motete Dousunda is the perfect environment for doki doki. The whole show is about one rotten girl’s reactions to various stimulating scenes, at the center of which is the heart! Kae is also not a particularly mature girl and she’s obsessed with anime, so her use of doki doki fits in well with her character. It regales her more innocent and naïve understanding of love, as her only experience with it has been through Boys Love manga and fawning over hot anime boys (but hey, not like we can point fingers). When she’s alone with one of the guys in her class and he’s touching her shoulder, she says ‘sugoku doki doki suru’ which roughly translates to ‘My heart is beating so fast’. Doki doki has a connotation of nervousness and isn't used when you're just overcome with love. This is revealed by Kae’s inner monolog of her panic in trying to keep her perverted homo-erotic thoughts under control!