Well we all know that mochi is a plain, sticky glutinuous rice (mochi-gome) confectionary, usually eaten outside of japan in the daifuku form.
The "original" mochi is the plain mochi. The sweets made with mochi, such as daifuku, "developed" from plain mochi. So, in Japan, the term "mochi" refers to the plain type
The "kiri-mochi" you mentioned is plain mochi (glutinous rice that has been pounded into a sticky blob) that has been hardened and cut into small rectangles. FYI, mochi is cut into rectangles in eastern Japan. People in western Japan prefer round mochi (maru-mochi).
Mochi is eaten in many ways. Freshly pound mochi is most delicious and is eaten with anko, grated radish and soy sauce, etc. When it cannot be eaten fresh, mochi is hardened for preservation.
Kiri-mochi is very often eaten toasted (until it starts cracking and puffing), sprinked with soy sauce and wrapped in nori. This is called "isobe-maki."
It can also be toasted, dipped briefly in hot water and coated with kinako (powdered soybean) and sugar to make "kinako-mochi."
During the New Year season, mochi is eaten as in "zouni," a soup with lots of vegetables and meat (chicken, fish, etc.). The type of soup, vegetables, meat used in this recipe vary by region in Japan.
This is an example:
Zouni recipe
For those who have experience with kiri-mochi, do you need to soak these vacuum sealed packs of kiri-mochi prior to usage? Furthurmore, is kiri-mochi made the exact same way as the usual mochi in daifukus? Is it actually possible for me to make my own kiri-mochi?
No need for soaking. Unwrap the mochi and toast. Also, unwrapped mochi can be soaked into water to restore it into its sticky form, warmed and eaten like fresh mochi--although this may be difficult to manage.
As I mentioned earlier, kiri-mochi is made from pounded rice. On the other hand, mochi for daifuku is made from glutinous mochi rice that has been grounded and manufactured in special processes into joshin-ko, shiratama-ko and other rice powders.
To made kiri-mochi yourself, you need a large mortar and pestle. Steam glutinous rice and pound in the mortar, pestle and hand (all kept constantly wet) while hot until the grainy look is gone and the blob is smooth. This is a tough job (therefore many use store-bought mochi), but homemade is the best way to eat mochi.
Hope this helps!