In general, あたし sounds casual or childish as compared to わたし. Unlike わたし, you should not use あたし in business settings. This song is an "image song" of a character called Falsita, and according to videos on the net, her normal first-person pronoun is 私（わたし）.

アタシヲアイシテ is written in katakana, which implies this particular line belongs to a different context. Have you ever seen an all-katakana sentence like this said by a yandere character or someone in a fury? In this case, アタシヲアイシテ represents her bare and strong feelings, and that's why she temporarily switched from あたし to アタシ.

Similarly, a male character who normally uses 僕 may temporarily switch to 俺 when he is excited. Changing the first-person pronoun is one of the common ways to show one's emotion.

In general, あたし sounds casual or childish as compared to わたし. Unlike わたし, you should not use あたし in business settings.

アタシヲアイシテ is written in katakana, which implies this particular line belongs to a different context. Have you ever seen an all-katakana sentence like this said by a yandere character or someone in a fury? In this case, アタシヲアイシテ represents her hidden but strong feelings, and that's why she (Falsita) temporarily switched from 私 to アタシ.

Similarly, a male character who normally uses 僕 may temporarily switch to 俺 when he is excited or angry. Changing a first-person pronoun is one of the ways to show one's emotion.

In general, あたし sounds casual or childish as compared to わたし. Unlike わたし, you should not use あたし in business settings. This song is an "image song" of a character called Falsita, and according to videos on the net, her normal first-person pronoun is 私（わたし）.

アタシヲアイシテ is written in katakana, which implies this particular line belongs to a different context. Have you ever seen an all-katakana sentence like this said by a yandere character or someone in a fury? In this case, アタシヲアイシテ represents her bare and strong feelings, and hence the use of アタシ.

In general, あたし sounds casual or childish as compared to わたし. Unlike わたし, you should not use あたし in business settings. This song is an "image song" of a character called Falsita, and according to videos on the net, her normal first-person pronoun is 私（わたし）.

アタシヲアイシテ is written in katakana, which implies this particular line belongs to a different context. Have you ever seen an all-katakana sentence like this said by a yandere character or someone in a fury? In this case, アタシヲアイシテ represents her bare and strong feelings, and that's why she temporarily switched from あたし to アタシ.

Similarly, a male character who normally uses 僕 may temporarily switch to 俺 when he is excited. Changing the first-person pronoun is one of the common ways to show one's emotion.