Ah, the soothing sound of the Cicada… Of course it may not sound relaxing, or even pleasant to hear. so why is it used within eastern anime such as the Japanese film The Girl Who Leapt Through Time?
It's all down to culture.
The Cicada is an insect that emerges from the ground each summer. It's song, called Tsuku-tsuku Boshi, is heard towards the end of summer and is frequently used in media to signify the summer season. It is effective way to add emotional and nostalgic feelings of the summer, such as long lazy days, free time and peace.
It wouldn’t be as effective to use the song of the cicada to convey summer and it’s related emotions in other cultures. However, Japanese media such as anime television and films use it with great effect. This small insect may be an annoying sound for some but for many in Japan, will bring back childhood memories of lazy summer days. it's common inclusion within Japanese media shows how the sound of this insect helps define heritage and culture.